This is a list of the characters appearing in Strike the Blood. Contains unmarked spoilers (read at your risk).
The male lead, Kojou was an Ordinary High-School Student until an incident three months ago where inherited the powers of the world's most powerful vampire, The Fourth Progenitor. Despite this he tried to live a normal life for fear of using his powers. Despite his best intentions he kept getting involved in various supernatural affairs as more and more threats come to Itogami Island.
- Accidental Pervert: All the time.
- Accidental Pornomancer: A rare example that uses bloodsucking as a substitute for sex, but nonetheless, plays the rest of the trope completely straight.
- The Ageless: Not yet, but it is stated vampires have this type of immortality, so while he isn't exactly old yet, he has the potential to become so.
- Apologizes a Lot: Due to all the mischief he often finds himself in with the girls. Sometimes they accept it, other times they go into Clingy Jealous Girl mode on him.
- Badass Longcoat: For much of the Labyrinth of the Blue Witch arc. You can thank Yuuma for that one.
- Barrier Warrior: After awakening Regulus Aurum, he gains the ability to create bio-electrical barriers.
- Beware the Nice Ones: Kojou is kind of a slacker, easy-going, and generally friendly, but he's still one of the powerful vampires in existence and has one hell of a temper when it gets going.
- BFS: Taken to its illogical extreme; Kiffa-Ahtel is over 100 meters long.
- Big Damn Heroes: Makes an absolutely epic entrance in episode 22 to save Yukina and Kanon.
- Bilingual Bonus: All of Kojou's familiars have Latin and Arabic names based on stars in the Zodiac.
- Brilliant, but Lazy: Kojou's actually pretty intelligent, and has shown great leadership qualities, but it's hard to see this most of the time because of his laid-back attitude and habit of rushing into things without thinking. As turns out, there's a reason for this. Back in middle school, he used to be an enthusiastic basketball player, and was even the Star Athlete of the school team. And that was the problem. He was so driven that he began to overshadow the rest of the team, and the game gradually became less of a "team" sport and more of a one-man show; and they resented him for it. It eventually go to the point that he was the only one putting any effort into their games because the rest saw no point in trying. He quit the sport soon afterwords, and since then he's been reluctant to put much effort into anything because he doesn't want to elevate himself above others like that again.
- Calling Parents by Their Name: He and Nagisa both call their parents Mimori and Gajou rather than one of Japanese's forms of "Mother" and "Father"
- Calling Your Attacks: "I, Akatsuki Kojou, Successor to the blood of Kaleid Blood, now release thy restraints. Come forth, Xth Familiar, Y Z!"
- "Give me a break..."
- "WHAT THE HELL?!"
- "From here on, this is MY fight!"
- Chekhov's Gun: Believe it or not, his blood becomes crucial in "Fiesta for the Observers", as it allows Natsuki to recover her memories for a short time, enough to take Aya's memory-stealing grimoire away and rip off her Guardian.
- Chosen Conception Partner:
- La Folia off-handedly expressed an interest in having Kojou's child.
- A ship full of beautiful female hostages directly asked him to impregnate them. Mostly because it would give them political leverage.
- Clueless Chick Magnet: He has managed to win the affection of several girls (including a man-hating possibly-lesbian) as well as at least one guy. With a few exceptions, he is mostly oblivious about that.
- Dude Magnet: If every vampire on Vatler's yacht lusting for him is any indication.
- Crouching Moron, Hidden Badass: He isn't stupid enough to qualify as an Idiot Hero, but he's still laid back, lazy and usually lacking any drive outside of fights. He also happens to be one of the most powerful vampires in the world.
- Daywalking Vampire: Sunlight doesn't appear to affect him. He does express some discomfort in his first episode, but that seems to be more of a standard human problem with heat rather than a weakness to sunlight.
- Destructive Saviour: Let's see here: uber-powerful vampire, trouble magnet, well meaning do-gooder, Political shitstorm in the making, hopeless with women... Yeah, any situation he gets involved in is going to turn messy. note . Several characters, particularly Natsuki and members of the Lion King Organization, are aware of this trope and frequently try to block him from getting involved in the first place.
- Emergency Transformation: Was transformed into a Blood Vassal, a pseudo-vampire, to save his life several years before the series started, before becoming a full fledged Vampire later on.
- Fangs Are Evil: You won't see them unless he's baring his teeth in anger or his vampiric urges are acting up, both of which are big "Uh Oh" signs.
- "Freaky Friday" Flip: Wakes up in the body of Yuuma Tokoyogi in the "Labyrinth of the Blue Witch" arc after she kissed him the night before. He is thoroughly confused and spends most of the arc trying to find his own body, which he does after defeating Yuuma.
- Friendly Neighborhood Vampire: Taken Up to Eleven because as the Fourth Progenitor, it's rather expected that he should be trying to create his own dominion and conquer lands and vassals for himself, but he doesn't care about any of that and just wants to be an Ordinary High-School Student.
- Harem-Powered: Kojou is a Pregenitor vampire with the ability to summon highly destructive familiars. However, the familiars will not respect a "virgin" vampire and will only awaken if he drinks blood. In addition to that, some of his familiars require multiple different "blood donors", some require specific types of blood (or Life Energy) and some just become bored from receiving blood from the same partner over and over. Because of that, Kojou is required to keep a harem of women (and possibly men) to access his powers.
- Have I Mentioned I Am Heterosexual Today?: Due to his obliviousness about people's feelings for him and him being on friendly terms with a Lord of the Warlord's Dominion, Asagi is convinced that he is into men.
- He Cleans Up Nicely: In the "Labyrinth of the Blue Witch" and "Fiesta for the Observers" arcs.
- I Don't Want to Ruin Our Friendship: In episode 18, an insecure Asagi asks why Kojou never seems interested in her body and offers a peek. His answer is basically that he's really tempted, but he doesn't want to do something Asagi would wind up hating him for, because she's very special to him.
- I Just Want to Be Normal: Downplayed. He expresses annoyance with his powers more than anything else because he has no idea what he should do with them. This attitude gradually disappears as he learns how to control his powers and takes a more active role in defending the city.
- Immortality: To the point where he can actually come back from the dead.
- Impaled with Extreme Prejudice: Happens to him an awful lot, really, but most notably at the hands of Kanon Kanase and Aya Tokoyogi's Guardian.
- In the Hood: As part of his Non-Uniform Uniform.
- Let's Get Dangerous!: He can deliver a Curb-Stomp Battle if he absolutely has to.
- Lightning Bruiser: Though he has problems controlling his speed and therefore occasionally collides into things.
- Meaningful Name: "Akatsuki Kojou" roughly means "Daybreak Castle", alluding both to his status as a vampire and creature of the night, but also his status as a Progenitor and thus destined lord of his own domain.
- Mistaken for Gay: Mainly by Asagi, since he seems to be in a bit of over-friendly terms with Vatler and Kira.
- Mr. Fanservice/Heroic Build: Episode 12 reveals that underneath his heavy clothing, he's actually really ripped.
- Muggle Born of Mages: Koujo used to be this before becoming Avrora's Blood Vassal and then the Fourth Progenitor. Nagisa and their paternal grandmother are powerful spirit mediums, Mimori possesses Psychometry and Gajou has access to a form of Hyperspace Arsenal. Downplayed in that Gajou's powers are accquired rather than innate, despite his own mystical heritage.
- Mundane Utility: At one point Kojou tries to do some electrofishing... using Regulus Aurum. It goes about as well as you'd think.
- Names to Run Away from Really Fast: In-Universe. The name "Akatsuki" is said to carry the same implications as "Lucifer" in this world.
- Nice Guy: Genuinely wants to help others, and cares about his friends and family above all else.
- Oblivious to Love: Downplayed, since he seems at least somewhat aware of the women around him's attraction to him.
- Off with His Head!: Suffers a decapitation at the hands of Combat Deacon Eustach, though his regenerative powers allow him to get better.
- One-Man Army: As a Progenitor, he's the equivalent of a global superpower.
- Our Vampires Are Different: He can walk around in broad daylight, summon familiars, and seems to still be a living, breathing creature rather than The Undead. Further, his blood thirst is connected to sexual desire, and he can temporarily sate it by drinking his own blood rather than others, although this reduces his power and ability to use his familiars.
- Person of Mass Destruction: He has a total of twelve Familiars (though he only unlocks them one by one). A single one of them can destroy an entire region of the city in a matter of minutes.
- Red Baron: "Kaleid Blood". He inherited the title from Avrora Florestina, the previous Fourth Progenitor.
- Red Eyes, Take Warning: His eyes turn red whenever he is subject to his Blood Lust or using his powers.
- Reluctant Warrior: He would rather avoid fighting, but his opponents never really offer him that option.
- The Renfield: Started off as Avrora's "Blood Vassal," a pseudo-vampiric, immortal servant created by a Vampire grafting some of their flesh, often a bone like a rib, into a human's body.
- Sick and Wrong: When Asagi suggests that he and Vatler may be lovers, Kojou says the thought "gives him goosebumps", and his face expresses pure disgust.
- Signs of the End Times: According to Kanase Kensei, a Fourth Progenitor in a world where only 3 are supposed to exist marks that bad things are coming
- Sliding Scale of Vampire Friendliness: A very friendly version:
- His blood craving can be sated with his own blood. In effect, it's equivalent and connected to sexual lust, and the more aroused he gets the harder it becomes to fight his urges. Yuuma and Sayaka push him to his limit in Episode 19 to the point that when he starts to feed on them, his voice is almost maddened with desire.
- Appearance-wise, he is a very handsome Bishounen with no bestial or demonic transformations (that we know of) aside from Cute Little Fangs. Likewise, he has no weaknesses to holy relics or sunlight, nor a dependency on darkness or other repulsive things.
- His powers require him to drink blood before unlocking them, but in general, he's very keen to avoid doing this on unwilling persons. While it's also possible that there could be other unpleasant sides to his abilities, Kojou still tries very, very hard to avoid using them on people unless he has no choice.
- Stock Light-Novel Hero: Kojou has silver hair and often wears a hoodie, but other than that, perfectly fits the style of an LN hero. He's the Fourth Progenitor, by his own admission "the most powerful vampire in the world". Progenitors can summon an entire army of familiars—each one by itself a Person of Mass Destruction, but to awaken familiars he must drink blood. The familiars literally won't respect a "virgin" vampire, and some of them still won't respond if he only drinks blood from the same people over and over, thus requiring him to acquire an Unwanted Harem. Even if he didn't have to, though, Kojou's power, good looks, and desire to protect others draws a large number of girls (and some men) to him.
- Superpower Lottery/Combo Platter Powers: Aside from the traditional enhanced strength, speed, stamina, Immortality and eternal youth, each of his Familiars gives him a specific ability:
- An Ice Person: "Alrescha Glacies", Familiar #12. It is currently in possession of the fragment of Avrora residing within Nagisa.
- Blow You Away/Make Me Wanna Shout: "Al-Nasl Minium", Familiar #9.
- Dishing Out Dirt: "Cor Tauri-Sucinum" Familiar #2.
- Gemstone Assault: "Mesarthim-Adamas", Familiar #1
- Living Weapon/Gravity Master: "Kiffa-Ahtel", Familiar #7
- Making a Splash/Time Master: "Sadalmelik-Albus", Familiar #11
- Mysterious Mist: "Natra-Cinereus", Familiar #4
- Playing with Fire: Familiar #8, a Manticore which he neither knows the name of or has control over.
- Reality Warper: "Al-Maisan Mercury", Familiar #3.
- Shock and Awe: "Regulus Aurum", Familiar #5.
- Super Strength: Although he doesn't use it much, as his familiars pack much more of a wallop.
- Taking the Bullet:
- Takes a swing from Rudolf Eustache's gigantic axe in order to shield Yukina. The Combat Deacon then proceeds to grind his axe even further, decapitating him. Naturally, his regenerative powers allow him to survive that.
- Takes the brunt of the Wiseman's assault, causing him to be turned into metal.
- Theme Naming: Each of his Familiars so far have been named after stars in the Zodiac constellations.
- They Just Dont Get It: No matter how Natsuki-sensei yells at him, smacks him around, or gives him grief, he just can't help calling her Natsuki-chan, and it's not induced by malice or mischief either.
- Trauma-Induced Amnesia: Can't really explain how he became the Fourth Progenitor because his own memories of the incident are a scrambled mess, and cause him quite a bit of anguish whenever he tries to recall them.
- Unskilled, but Strong: Kojou can't use a majority of his Familiars, is not particularly good at fighting (To the point where Yukina can kick his ass if he doesn't blast her with his Familiars) and generally doesn't have the mindset for combat. He compensates by having a ridiculous amount of raw power and an absurdly powerful Healing Factor. According to Yuuma, Kojou's mana supply saved her from sacrificing 100,000 people to fuel the ritual needed to break the Prison Barrier's defenses.
- Vegetarian Vampire: He tries to be this at first, feeding only on his own blood to avoid biting people. It works, but has the sad side-effect of preventing his familiar from obeying him. As the series progress, girls gradually allow him to drink part of their blood so he can get control over his familiar.
- Walking Disaster Area: Partially because of his status as the 4th Progenitor, partially because Itogami City atracts all sorts of weirdness, and partially because he he's too darned nice, Kojou often finds himself neck deep in trouble.
- Wild Card: Since Progenitor's are the biggest, baddest players on the world's stage, his very existence has the potential to wreak havoc with the global balance of power. Naturally, this makes him the center of a lot of unwanted attention. (hence the above trope)
- World's Strongest Man: Referred to by various characters as the "World's Strongest Vampire". This may be a hereditary title that he got from Avrora, as he doesn't exactly live up to the claim... at first.
The female lead and an Attack Mage of the Lion King Organization, Yukina was sent to observe Kojou and in the event that he proved himself hostile, assassinate him. This quickly goes out of the window as she develops feelings for him.
- Accidental Proposal: Subverted. She asks Kojou to stay by her side "forever", which makes the other girls question if she just proposed. She claims That Came Out Wrong.
- Action Girl: To the point where she is often a legitimate threat to some very powerful opponents on her own.
- Adorkable: Sweet tempered, unfailingly well-mannered, not to mention painfully sincere and earnest about everything.
- Anger Born of Worry: Several times. But most notably after Kojou regenerates from decapitation.
- Anti-Magic: Her Schneesturm Wölfin damages magic in it's proximity and outright destroys it given enough time.
- Badass Adorable / Cute Bruiser: Yukina is a short and very cute high school girl who can kick your ass.
- Badass in Distress: During the Nalakuvera incident she is kidnapped, along with Nagisa and Asagi, by Christoph Gardos' terrorist group. Not only does she escape by herself, but by the time Natsuki arrives to help her, she has already taken down two guards and even forced Gardos himself into retreat, cutting off one of his hands in the process.
- Bathing Beauty: Frequently caught in situations where she barely has the chance to dry herself properly, thereby wetting her clothes and (involuntarily) showing off her smooth skin and trim figure to Kojou. Played straight when he stumbles into her while she was bathing in Episode 11, though he wasn't lying when he said that not only didn't he see her, he was actually looking at La Folia Rihavein.
- Battle Couple: She and Kojou make a good team. Her Anti-Magic abilities let her get around pesky barriers and other abilities that he can't get past, and he can just smash everything else with brute force. Thus, she deals the final blow against Arc Villains just as often as he does.
- Berserk Button: She doesn't like people peeking under her skirt. Or peeking altogether, for that matter.
- Blade on a Stick: Schneesturm Wölfin, which is German for "Blizzard Wolf".
- Bodyguard Crush: Played With. She was originally sent to "observe" him and take him out if he turned out to be dangerous. When she finds that he's generally a good guy, she switches her "observation" rationale from assassination to protection, as it allows her to stick by his side. In episode 19, when Kojou is almost fatally wounded, she asks him to stick by her "forever" so that she can protect him.
- Break the Cutie: Suffers this in Episode 3 when Kojou gets decapitated right in front of her by the Combat Deacon. She gets better when he regenerates.
- Calling Your Attacks: "I, Sword Shaman of the High God, as a priestess of the Lion, beseech thee... Dawn light of exorcism, spirit wolf of snowy mist, grant me the divine might of thy steel, that I may smite a hundred evil spirits!"
- Catch-Phrase: "Don't worry, Sempai; I am your observer, after all!" (Angelic reassuring smile) and "No, I'm not angry at all, Sempai" (Angelic 'not' reassuring smile)
- Child Soldier: She was adopted by the Lion's King Organization for the express purpose of being raised as a Sword Shaman.
- Clingy Jealous Girl: She gets angry and begins speaking in a really condescending and insincere tone if Kojou mentions other girls or does anything inappropriate, even if it's accidental.
- Interestingly enough, she's not as jealous when she hears that Sayaka offered her blood to him in episode 8. In fact, she was more worried that he may have forced himself onto her, but was relieved to find out that wasn't the case.
- In episode 10, after Kojou and Yukina get dropped off on an abandoned island/research facility, he says that in the worst case scenario, they'd have to live there alone, and mentions that it'll really suck. She turns around and breaks a rather large branch off a nearby tree. When he asks if she's mad, she claims to be making a landmark for reference, while angrily shaking the branch thinking about his previous comment.
- In episode 12, she's there when La Folia kisses Kojou, but she doesn't react to that. What she reacts to is learning that Asagi had also kissed Kojou back in episode 8.
- In episode 19, she gets angry when Yuuma tricks Kojou into kissing her. When he defends himself by pointing out that it was a Forceful Kiss, she claims he's too "unguarded" and she's just displaying Anger Born of Worry.
- In episode 22, after Kojou does a Big Damn Heroes for her, she says that she needs to keep more of an eye on him, because he keeps getting into trouble, and hooking up with all these unfamiliar women.
- Clueless Dude Magnet: She is quite popular among the boys at school, to the point some of them came to beg her to become a cheerleader. Apparently, she never noticed.
- Double Standard: Abuse, Female on Male: Downplayed, she is nowhere near as bad as most female main characters in shows of a similar genre, but still, she isn't above some Disproportionate Retribution to some of Kojou's Accidental Pervert and Oblivious to Love moments, and it's always played for comedy.
- First Girl Wins: If episode 23 and 24 are anything to go by...
- Fish out of Water: When she first goes shopping with Kojou in episode 2, she's amazed at all the types of weapons they sell at the hardware store, such as golf clubs, pressure washers, and chainsaws. He has to correct her as to what their intended use is for. When she tries to comment that mixing two types of cleaners can be used to make explosives, he immediately stops her from saying any more.
- Holy Hand Grenade: Played with. Her powers and staff are designed to cancel out all types of magic, not just the "bad" kinds. However, it's theorized that this is because magic in itself is unnatural and negating it is "returning the world to how it was meant to be".
- Honey Trap: The Lion King organization actually sent her, along with Sayaka, to be Kojou's "mates", as Yaze is his real observer. She remains unaware of this, however.
- How Dare You Die on Me!: To Kojou in episode 22, when he's turned into metal.
- Informed Attractiveness: It's not that Yukina isn't attractive. But, we're flat out told several times that she's absurdly gorgeous compared to other middle school girls in her class. This is despite the fact that she's actually got one of the most plain designs in this series' character roster. She doesn't have anything really special about her looks, whether it be a distinctive style of dress (like Natsuki), distinctive eye shape or color (like Kanon or La Folia), or distinctive hairstyle or shape (like Asagi or Sayaka). Even Nagisa, who is her classmate, has something special about her appearance. Compared to the other characters, there's nothing about Yukina that stands out—especially when Only Six Faces is taken into account.
- In Love with the Mark: She thought that she was actually meant to assassinate Kojou, but his immortality and her crush on him quickly leaves that mission in the dust.
- Insecure Love Interest: Due to her Clingy Jealous Girl tendencies, along with the large harem of women interested in Kojou, she's always suspicious of anything he does with another woman, even if he's completely innocent.
- Keigo: She uses exclusively polite and formal Japanese in her everyday speech, which with her friendly and polite manners marks her out as a Yamato Nadeshiko in the making. She even prefers to refer to new friends (like La Folia) by their formal names even after they offer to allow her to use affectionate nicknames.
- The Lancer: she is Kojou's most trusted companion and fighting partner.
- Little Miss Badass: A waifish middle-schooler trained in magical combat and using one of the most powerful weapons in the setting.
- Nice Girl: Bright, sweet, well-mannered and kind-hearted; every home should have one.
- Parental Abandonment: She was sold to the Lion King organization as a baby by her biological parents.
- Phrase-Catcher: "No, Senpai. This is our fight!" (In response to Kojou's Catch-Phrase above.)
- Pint-Sized Powerhouse: And very cute and cuddly to boot.
- Punched Across the Room: "Pulsation", which involves her applying both her hands to a target who are then hit with an extraordinary amount of force.
- Reluctant Fanservice Girl: She really doesn't like being ogled or looked at with perverse desire. Except on certain special occasions when she gives Kojou permission.
- Sacred First Kiss: With Kojou in Episode 12 (she does it hastily to prevent La Folia from getting it in her stead). She discusses it with her classmates in Episode 21 and stops just short of spilling the beans—which makes them explode with curiosity.
- Sempai Kouhai: Kojou's kouhai, as well as Kirasaka's kouhai and former roommate at High God Forest.
- She's Got Legs: Via a Dangerously Short Skirt.
- Shock and Awe: Her staff exhibits lightning and electrical abilities in addition to power nullification.
- Small Girl, Big Gun: Her spear is as long as she is tall.
- Thousand-Yard Stare: She suffers one in episode 3 after Kojou takes a blow intended for her. She's splattered with his blood, then his body falls limp on her, and detaches from his head as she's holding it after Eustach grinds his axe some more into him. Her Big "NO!" scream right afterwards adds to the trauma she just witnessed. Fortunately for her he gets better.
- Voluntary Vampire Victim: The very first person who willingly offered her blood to Kojou, and thus the default option thereafter. In fact, if she determines that another woman has given him their blood, she becomes EXTREMELY upset about it.
- Weak, but Skilled: In contrast to Kojou, Yukina's a normal (relatively speaking) human, but can go toe-to-toe with some pretty nasty customers thanks to years of training.
- Why Did It Have to Be Snakes?: Doesn't like getting into planes, especially not when she's in high altitude.
Natsuki is an English teacher at Ayami Academy and she is also a powerful attack mage called "The Witch of The Void". She claims to be in her mid 20's in spite of her childish appearance. She is one of the few people who knows that Kojou is the Fourth Progenitor.
- Animated Armor: The Golden Guardian, which is her familiar and the archrival of Aya's Le Ombre.
- Astral Projection: She is able to project realistic copies of her own body, such as the Natsuki everyone knows and talks with in school; the real Natsuki resides in a maximum security magic prison in order to keep the seal on Aya Tokoyogi.
- Badass Adorable: She has the appearance of a cute little girl dressed like like a Gothic Lolita. She also happens to be one of the most powerful mages in existence.
- Barrier Maiden: She or rather her real body keeps the seal on the Demon Barrier Prison, which includes some of the most dangerous magic world criminals, such as Aya Tokoyogi. Only by fatally wounding Natsuki is Aya, along with the other inmates, able to escape her prison.
- Berserk Button: Do not call her Natsuki-chan. At the absolute best of times, it irritates her. Kojou keeps doing it anyway.
- Chain Pain: Can manifest countless chains out of thin air at will, often to restrain opponents or minimize the damage caused by ongoing fights.
- Cool Teacher: A bit rough around the edges but she's definitely this.
- Cute Witch: Although she insists on being in her twenties, somewhat subverting this trope.
- Dark Is Not Evil: She's mostly dressed in black, and she has control over the Power of the Void, but she's the closest thing to a Big Good in this story.
- Elegant Gothic Lolita: How she dresses normally, although she puts on the school uniform in Episode 13, catching Kojou and Yukina off-guard.
- Embarrassing Nickname: Do not address her as Natsuki-chan.
- Impaled with Extreme Prejudice: Is on the receiving end in The Stinger of the "Labyrinth of the Blue Witch" arc, by Yuuma's guardian, revealed to be Aya's instead. She survives, but gets her memories stolen by Aya's Grimore 014, reverting her to a childish personality. She fully recovers by the end of the "Fiesta for the Observers" arc.
- Insistent Terminology: Remember, it's Natsuki-sensei!
- Jerkass Façade: She tries to come off as colder than she really is, but the disguise is paper-thin.
- Little Miss Badass: She cooly and calmly defeats several opponents that even the main characters have trouble with. Most people aware of who she is are scared shitless of her.
- Magical Incantation: Makes a long-winded one in order to rip Le Ombre away from Aya and give Le Bleu back to Yuuma.Natsuki: "My name is the Void. I am she who reduces broken vows to ash consumed by eternal flames. Tear off your yoke of black blood, and return whence you belong! Offer your sword to the blue maiden - the blessing of your honoured soul!"
- Older Than They Look: She is 26, yet looks like a grade-schooler. This is because her real body has been asleep for years in the Demon Prison Barrier in order to keep the seal on the criminals locked in there.
- Parasol of Prettiness: Which can rapidly turn into a Parasol of Pain.
- Power of the Void: Though in this universe, Void seems to translate as "space".
- Reasonable Authority Figure: She doesn't actively get in the way of Kojou and Yukina's actions because she knows they're able to come out on top in the end.
- Red Baron: "The Witch of The Void".
- Sailor Fuku: In episode 13, where she claims that it's a disguise to try and catch some of the molesters that have been plaguing the metros recently. Kojou is quick to reply that she looks better in it than her normal garbs.
- Secret Keeper: One of the few people to know right from the beginning that Kojou is the Fourth Progenitor.
- Split Personality: She has an absolutely hilarious backup personality by the name of Natsu-Kyun.
- Stern Teacher:
- Lectures her students when she catches them out late at night on a school night, and then calls them into her office to scold them more.
- When she catches Kojou and Asagi skipping classes, she tells them to do three times the work in make-up assignments.
- The Stoic: Almost always puts on a serious face.
- Teleporters and Transporters: Most of the time, she is able to come up behind her opponents by way of her space manipulation.
- Token Mini-Moe: Initially, although she gets competition from Astarte after her HeelFace Turn. Takes the spot again as Natsu-Kyun.
A childhood friend and classmate of Kojou, she is an expert programmer and works for the Manmade Island Management Corporation. She has a crush on Kojou. Despite knowing the island is deeply connected to supernatural powers and creatures, she has no idea that her friends are among them. She is nicknamed Cyber Empress.
- Action Survivor: Protects a de-powered Natsuki during the "Fiesta for the Observers" arc.
- Alliterative Name: Asagi Aiba.
- Aren't You Going to Ravish Me?: To Kojou in episode 21. After waking up half-naked in his bed, she gets emotional and teary-eyed over the implication that Kojou might have done something to her while unconscious. An embarrassed Kojou assures her that nothing happened, and after he finally convinces her, she tells him, "You're useless".
- Awesomeness by Analysis: In the span of a few hours she manages to not only analyse the Nalakuvera, but create a self-destruct command based on its use of sound commands.
- Badass Bookworm: She's a very skilled hacker, and she's responsible for the destruction of all of the Nalakuveras, including the queen unit.
- Cannot Spit It Out: Initially. Compared to most cases in fiction though, she is relatively quick to get better at it.
- Childhood Friend/Childhood Friend Romance: She's known Kojou for a good while and has feelings for him.
- Clingy Jealous Girl:
- In episode 2, she sees Kojou walking with Himeragi outside of school and later questions him about it.
- In episode 3, Natsuki-sensei tells him to report to teacher's office with the middle school transfer student that all the boys were going crazy over. When one of the female classmates angrily states that Kojou already has Asagi, he says that they're Just Friends. Asagi then rips up his world history report.
- In episode 4, she angrily confronts Kojou and Himeragi after hearing them talk about "losing blood" and "safe days".
- In episode 6, she confronts Himeragi again and directly questions her about her relationship with Kojou.
- In episode 11, she demands to know what Sayaka's relationship to Kojou is after the two search for his whereabouts.
- In episode 12, she witnesses La Folia kiss Kojou and gets extremely angry about it.
- In episode 18, she expresses jealousy over Kojou's friendship with the Pretty Boy, Vatler, and figures that the only possible reason he could show no interest in her body is if he's gay.
- Subverted in episode 19. When she walks in on Himeragi apparently proposing to Kojou, she's more surprised by her boldness than angry. (Although she could have just been teasing Yukina as well.)
- Cry Cute: Both in the brief flashback, and after waking up in Kojou's bed.
- Delinquent Hair: A flashback to a few years ago reveals that Asagi used to have black hair but dyed it blonde at some point.
- First Kiss: With Kojou in The Stinger for Episode 8.
- Forceful Kiss: Same as First Kiss, above.
- Foreshadowing: During the "Alchemist's Return" arc, she is fatally injured by Wiseman's blood and is left to die. While Nina Adelard took the necessary steps to keep her body safe from Wiseman's contamination, she herself recovered from her injuries in record time, with no recollection of the incident whatsoever. This is because she is the Priestess of Cain, and is thus tied to Itogami Island; as long as she remains on the island, she cannot die.
- Heroic Sacrifice: She attempts one in Episode 24. Fortunately, the heroes save the day, making it unnecessary.
- Honey Trap: Invoked and subverted. At Yaze's suggestion, she attempts to charm Kojou in the morning in his bed, but he barely even notices before going back to sleep.
- Immune to Fate/Immortality: As the Priestess of Cain, she cannot be killed by any means until she fulfills that destiny. It differs from Kojou's immortality in that events will simply align themselves in a way that results in her unconditional survival.
- Locked Out of the Loop: Doesn't know that Kojou's become the Fourth Progenitor, and he's reluctant to tell her out of concern for her safety. She finally finds out in the last episode of Strike the Blood II.
- Love Confession:
- Downplayed in Episode 8; after years of Cannot Spit It Out, Kojou still believes they're Just Friends. So after the "Warlord" arc, she asks Kojou to get a close look at her earrings, and then plants a Forceful Kiss on him and says "Now you know". Kojou stunned by this; however, four episodes later, he starts to ask her about the kiss (in front of the other girls), and she backpedals about its meaning.
- In Episode 24, Asagi has decided to make a Heroic Sacrifice to save as many people from the sinking Itogami Island as possible, and after begging Kojou to escape, she again brings up their kiss and starts to make a Dying Declaration of Love...but the phone cuts off before she can finish.
- Male Gaze: Several characters comment on her figure, which we get plenty of close-up shots of.
- Muggle Best Friend: To Kojou. She knows of the shiftier sides of the city and has been a Living Macguffin for an arc already, but she has no powers of her own besides her incredible tech skills. Subverted when we are told that she's the "Priestess of Cain", and her destiny is intertwined with the true reason behind Kojou becoming the Fourth Progenitor.
- Nerves of Steel:
- During the "Warlord" arc, she stands up to Gardos and his henchmen, and sabotages Nalakuvera, without losing her composure.
- In episode 17, she escapes from Kilika Giliga with a depowered Natsuki, never once losing her cool or wits, and staying one step ahead of him at all times.
- In episode 24, while everyone else is panicking and trying to escape Itogami Island before it sinks, she stays behind at her computer, doing everything she can to save as many people as possible.
- Patient Childhood Love Interest: She's doing this for Kojou. Even the kiss she gives him doesn't seem to change his mind, especially after she tries to play it off later on.
- Later is revealed in a side story that her daughter Moegi is in fact Kojou's too.
- Playful Hacker: Supposedly the best hacker on Itogami Island.
- Science Hero: Despite being an ordinary human, she's the best hacker the protagonists can get.
- Sexy Coat Flashing: Attempted, except using a school uniform rather than a coat. In an attempt to seduce Kojou, Asagi takes off her clothes in front of him, standing in a bra and panties. She waits for him to notice, but he refuses to turn around, to her disappointment.
- She's Got Legs: Even lampshaded by one of her classmates.
- The Smart Girl: Is almost always the go-to person when Kojou needs a helping hand on the technical matters.
- Tears of Joy: In Episode 21, when she thinks Kojou took her virginity while she slept. She's quickly disappointed by the truth.
- Tsundere: Type B towards Kojou.
Kojou's best friend and classmate. He knows that Kojou is the Fourth Progenitor even though he didn't tell him, and appears to have some connection with the Lion King Organization. He is an Esper who has the ability to manipulate special soundwaves, but needs certain drugs or enhancers to strengthen his abilities.
- Big Bad Friend: Played with; he actually is a member of the Lion King Organization sent to observe the Fourth Progenitor, a fact Kojou is unaware of. However, since the Lion King isn't clearly defined as antagonistic so far, calling him "bad" is kind of a stretch.
- Blow You Away: He can fly and control wind through the use of sound.
- Childhood Friend: To Asagi.
- Fantastic Drug: He uses a special kind of pills called "Hyper Adapters" to power up his Psychic Powers temporarily.
- Headphones Equal Isolation: Subverted, he's a rather popular guy in his and Kojou's class. The headphones are also an essential tool to use his sound control abilities.
- Make Me Wanna Shout: He is a sound-based Esper who uses special pills to power himself up.
- The Mole: He is Kojou's real Lion King observer, whereas Sayaka and Yukina are actually meant to be his "mates".
- Mundane Utility: He can use his extreme hearing to map out an area and see what's going on everywhere in it, similarly to how bats can use sonar to detect their surroundings. This is useful for his position as Kojou's observer, allowing him to track Kojou anywhere in their school at once.
- Non-Action Guy: Gloriously proven by Vatler, who takes him and his sound apparition out in a single magic blast.
- Platonic Life-Partners: With Asagi, despite being childhood friends.
- Psychic Powers: He's an Esper who can manipulate sound.
- Shipper on Deck: Actively encourages Asagi to confess her feelings to Kojou. as mentioned above, Lion King Orginzation are already trying set up Yukina and Sayaka as Kojou's "mates", which means that he's A). Locked out of the Loop, B). trying to set up another Honey Trap for his bosses, or C). actively working against his bosses' wishes. Only Time will tell
- Super Senses: Specifically, he has extremely good ears and can actually use them combined with his powers to use sonar response like a bat.
- Weaksauce Weakness: His manipulation of sound leaves him with very sensitive ears, so when Kojou accidentally shatters all the windows in their school while Yaze is using his Super Hearing, he winces from the pain and is left unable to use his powers for a good ten minutes.
- The Worf Effect: While showing off his powers for the first time in an attempt to save Asagi, Yukina and Nagisa from Christoph Gardos, he is quickly stopped by Vatler who defeats him by waving his hand in his general direction.
Nagisa is Kojou's little sister who attends the same school as Yukina and is in the same class 3-C. She is also a close friend of Yuuma Tokoyogi and is good friends with Yukina Himeragi and Kanon Kanase. Her mother is Mimori Akatsuki.
- Calling Parents by Their Name: Like Kojou she calls her parents by their given names. She also calls Kojou "Kojou-kun" rather than using some variant of Japanese Sibling Terminology.
- Clingy Jealous Girl: After the incident whereas Kojou saved her life on the mainland, Nagisa has shown extreme jealousy towards other girls who spend time with Kojou. This even applies to Asagi and Yukina, whom she originally openly encouraged.
- Dark and Troubled Past: A train crash that she only barely survived four years ago caused by demons resulted in her Primal Fear of them and may also be related to Avrora possessing her.
- Deus ex Machina: After Kojou is turned to metal, Nagisa appears and, demonstrating an ability she's never shown before, solves the problem, as she's possessed by Avrora and awakens the necessary plants a kiss on him, awakening a familiar that can undo the spell.
- First Kiss: Jokingly notes that hers would have been with Yukina had the Pocky punishment gone just a little further. It gets taken by Kojou instead, although Avrora had taken control of her body in order to activate Sadalmelik-Albus.
- First-Name Basis: Strangely, with Kojou and her parents. This is extremely unusual given how Japanese Pronouns work. She never adds a "-nii" to Kojou's name, or refers to her parents by anything other than their first name.
- Foreshadowing: According to Asagi, the doctors that saved her after the above incident said that she would be stuck in a coma for the rest of her life. Shortly after, we find out that she may be possessed by an outside entity who may have been behind her unlikely recovery.
- Genki Girl: She has hints of this, especially when she gets excited such as talking to Yukina.
- Kawaiiko: Has a very sweet little sister personality.
- Little Sister Heroine: Averted early on, but later subtle hints began to appear, such as the time she hit on Kojou after having her inhibitions removed by a succubus. Even later still, she openly began showing attraction to Kojou, including wanting to bathe with him again like they did when they were younger, and being openly jealous whenever he spent time with other girls.
- Locked Out of the Loop: Justified by the fact that she might never mentally recover if she found out that her brother was one of the supernatural beings that she fears so much.
- Motor Mouth: She tends to get overexcited and asks rapid-fire questions to others at times.
- Muggle: She does not know about Kojou's powers or those of any other characters from their school. However, she is revealed to be possessed by a portion of Avrora, which subverts this.
- O.O.C. Is Serious Business: During the Nalakuvera arc, she suddenly snaps into a trance and starts speaking with an echo, hinting that she may be possessed; this is later proven when she trashes Vatler and warns him about his ambitions.
- Primal Fear: If she sees a demon in their non-human form, she gets extremely scared and curls up in terror. This is caused by the demon-caused train crash that she only narrowly survived four years ago.
- Red Eyes, Take Warning: Her normally amber eyes turn red while she is possessed by Avrora.
- Shipper on Deck: She typically approves of any girl who tries to hit on her brother. Because Yukina is a classmate and close friend, she wants to root for her, but also thinks Asagi and La Folia are cute with him too. Sayaka was the only exception at one point, but only because every time Nagisa saw her, Kojou was hurt for one reason or another. Plus she says it'd be weird calling Yukina "O-nee" if she married Kojou. This later changes once her own feeling for Kojou begin to awaken.
- Soul Jar: Functions as one for Avrora Florestina, bearing a fragment of her soul.
- Token Mini-Moe: Behind Natsuki, Astarte, or Yume she's one of the youngest characters in the series.
- What Is This Feeling?: After spending time with Kojou on the mainland, she starts to resent seeing him with any other girls. She also becomes a lot more self-conscious of Kojou seeing her in a state of undress. She's confused by her reaction and openly wonders just what's going on with her.
Characters introduced in "The Right Arm of the Saint"
A Combat Deacon hailing from Lotharingia. He arrived in Itogami Island to retrieve a holy treasure belonging to the West European Church.
- Anti-Villain: Even Kojou and Yukina admit that technically, he is in the right to accomplish his goal, that is, retrieving the right arm of a saint from the West European Church, which is being used as the core of Itogami Island. The problem is he is completely uncaring of all the people he has to kill to reach said goal.
- Arc Villain: Of the "Right Arm of the Saint" arc.
- Awesomeness by Analysis: Is able to adjust Astarte's Familiar with divine vibrations after clashing once with Yukina's spear.
- An Axe to Grind: a gigantic battle axe that he wields with one hand.
- Badass Baritone: Kenta Miyake gives him a deep, manly voice.
- Badass Cape: A billowing one, just to emphasize how much ass he can kick during his arc.
- Badass Normal: He's literally just a religious man with a giant axe and a Homunculus ally, yet he still manages to be a big threat.
- Badass Preacher: A Combat Deacon of the West European Church who manages to steamroll Kojou twice.
- Bling of War: Armour of the Holy War, Alcazava, an armour that shines with an almost burning light.
- Church Militant: A Combat Deacon of the West European Church.
- The Coats Are Off: Ditches his cape in order to use his armour, Alcazava, to its full extent against Kojou.
- Even Evil Has Standards: At the end of episode 3, after he decapitates Kojou, he leaves a shell-shocked Yukina alone and goes to find the right arm of the saint instead of finishing her off like he had intended to originally.
- Eyepatch of Power/High-Class Glass: Has an opaque lens on his left eye.
- Futile Hand Reach: As he lays defeated, he reaches out to the Right Arm of the Saint before passing out.
- Holy Hand Grenade: The Alcazava shines so brightly, it even slightly singes Kojou, forcing him to back off a bit.
- Knight Templar: His motivation to retrieve the Right Arm of the Saint stems from the fact that it originally belonged to his religion, despite potentially causing Itogami Island to be destabilized at its core should the hand be removed from its pedestal. His order had tried the diplomatic route more than once to retrieve it, but Rudolf simply got fed up and decided to take matters into his own hands.
- Manly Tears: Upon finding the Right Arm of the Saint.
- Spock Speak: Well-spoken at all times, even to his adversaries.
- Starter Villain: Though his status as this does not decrease the threat he poses, as he defeats Kojou twice and nearly destroys Itogami Island.
- Well-Intentioned Extremist: It gets lampshaded by Kojou, who after finding out about Eustach's goal claims that he doesn't really have the right to stop him.
The homunculus servant of Rudolf Eustach. Possesses the power to summon a Familiar called "Rhododáktylos".
- Anti-Magic: Her Familiar has been adjusted with divine vibrations to nullify magic and cut through all kinds of barriers, effectively countering Yukina's spear. However, Kojou's newly awakened Regulus Aurum is able to weaken her vibrations, eventually succumbing to a combined attack by Yukina and Kojou.
- Bilingual Bonus: "Rhododáktylos" is Greek for "rosy fingers", a word used to describe the sky's coloration during a dawn or daybreak.
- Bullet Catch: Her Powered Armor allows her to stop in mid air bullets from the automatons guarding the Right Arm of the Saint.
- Catch-Phrase: "Accept", whenever she is given an order and is about to execute it; and "Complete", whenever she finishes her current order.
- The Comically Serious: One episode has her wearing a jack'o'lantern. She states it to be a preference when Kojou asks her about it.
- Defeat Means Friendship After Eustach's defeat, she is placed under Natsuki's command during the time she'd otherwise have to spend in jail.
- Defrosting Ice Queen: Originally indifferent to Kojou, she later shows signs of a crush on him when she chooses to side with him against her master, Natsuki. An exasperated Natsuki even bemoans Kojou's charm on women as being the reason for Astarte's defection.
- Emotionless Girl: Because she is a homunculus, she expresses little emotion and has no particular likes or dislikes. She eventually develops a Sugar-and-Ice Personality after some time.
- Energy Absorption: Her Familiar is capable of draining an opponent's powers, which is put to good use in the "Fiesta for the Observers" arc, where she defeats one of the Barrier Prison inmates.
- Expy: Of the cold and emotionless Index in John Pen Mode; both are voiced by Yuka Iguchi.
- HeelFace Turn: After Rudolf Eustach is defeated by Kojou and Yukina, Astarte is put under probation, then entrusted to Natsuki so she can watch over her.
- Ninja Maid: Natsuki uses her as one, down to actually dressing her as a maid.
- Our Homunculi Are Different: Rudolf Eustach created her so she can be the host of a Familiar.
- Powered Armor: Her Familiar can transform into one, allowing her to pilot it.
- Rei Ayanami Expy: Ticks most of the archetype's tropes; she has blue hair, is not human, is constantly emotionless, and often gets hurt when put into combat.
- The Stoic: She is not talkative and always says "Accept" in a dull, robotic tone whenever her master commands her.
- Summon Magic: She is the vessel of an abnormally powerful Familiar by the name of Rhododactylos.
- Tareme Eyes: Her eyes are noticeably droopy compared to the rest of the cast, although this is meant to convey her emotionless nature.
- When She Smiles: She's briefly seen smiling faintly when washing Nina Adelard's back in Episode 24's end credits.
- The Worf Effect: Suffers this on two occasions.
- During the Nalakuvera arc, she hastes to the rescue of Yukina, Asagi and Nagisa, but takes too long to summon her Familiar, allowing Christoph Gardos to shoot her before she can even finish her summon command.
- In the "Fiesta of Observers" arc, she absolutely owns Kiliga Gilika, only to be defeated by Gigliora Ghirardi soon after.
- You Gotta Have Blue Hair: If only to accentuate that she is not human.
- Your Days Are Numbered: Initially, she was slowly dying from using Rhododactylos and only had about a month to live. After Kojou brings the Familiar under control, her lifespan is normalized.
Characters introduced in "Messenger of the War King"
A friend of Yukina who was ordered by the Lion King Organization to take charge of multinational magical crimes in the Foreign Affairs Division.
- Absurdly Sharp Blade: By reversing the barrier of her sword to make the sword itself invulnerable, she can make it slice through anything like butter with a warm knife.
- Action Girl: Comes with being trained by the Lion King Organization and fighting supernatural beings since she was small.
- All Amazons Want Hercules: Invoked during the scene when she confesses that although she's grown used to playing Hercules for other girls, when Kojou does it for her, she finds it a welcome change.
- Badass Adorable: A knockout who can stop traffic with her beauty and stunning-proportions (not to mention her superb archery skills) who nevertheless surprisingly endearing and cute when she reveals her shy and vulnerable side.
- Because You Were Nice to Me: She gradually starts developing some feelings for Kojou due to his apologies for perverted acts, the fact that he seems to admire Yukina for more than just her looks, and because he doesn't consider her height a bad thing; something she was always insecure about.
- BFS: Her sword, Koukarin, is almost as big as she is. And she is big. When Aya Tokoyogi's Anti-Magic drains the sword of its magical energy, she actually cannot lift it.
- Bi the Way: Even after falling for Kojou, Sayaka is still very much in love with Yukina, and does her best to keep him away from her whenever they get too affectionate or close to each other.
- Boobs of Steel: When she meekly asks Kojou about her insecurities concerning her unusual height, he mistakes the matter to be about her breasts (which he had just accidentally copped a feel of) and reassuringly tells her "Don't worry; you know what they say, "guys like them big."" And yes, she is as powerful as she is stacked.
- Bow and Sword, in Accord: A variant, Koukarin can morph from sword into a bow.
- Bridal Carry: Kojou does this to her when they have to jump from subfloat to subfloat. While she tries to get him to let go at first, it later turns out that she was always the one to carry the other girls at High God Forest because of her height and actually appreciated that he did it.
- Calling Your Attacks: "I, War Dancer of the High God, as a dancer of the Lion, beseech thee... Enkuu of the aurora, Kirin of radiant light, who doth rule thunder and the heavens, come clad in raging fire, to pierce Hell's monstruous demons !"
- Catch-Phrase: "Don't *insert perfectly chaste action* me! I'll get pregnant!"
- Childhood Friend: She was Yukina's closest friend when they were younger.
- Childhood Friend Romance: How she seems to perceive their relationship. Even after falling for Kojou, she still loves Yukina dearly and is very protective of her.
- Clingy Jealous Girl: Toward Yukina, like you wouldn't know. Borders on Yandere when she is first introduced.
- Dangerously Short Skirt: As per usual for this series.
- Defrosting Ice Queen: Toward Kojou. Initially, she hates him for reasons such as jealousy for his relationship with Yukina, being a vampire, and supposedly being a Handsome Lech. However, she begins defrosting when he refers to her childhood picture as "cute" (apparently the first to have done so) and then doing a Bridal Carry to bring her aboard an enemy ship.
- Does Not Like Men: It's an actual phobia of hers, to the point where she has issues talking to a man over the phone. Kojou turns out to be an exception.
- Full-Name Basis: She always refers to Kojou by his full name, at first to address him as an enemy, and later because she becomes a Tsundere.
- Hates Being Touched: By men, to be specific. As stated below in Miss Conception, she has some mistaken ideas about how reproduction works.
- Honey Trap: Just like Yukina, the Lion King organization sent Sayaka to be Kojou's "mate". She does not know about this, either.
- Huge Schoolgirl: Almost as tall as Kojou, and has some insecurities based on her height.
- If It's You, It's Okay: She is clearly in love with Yukina and can't even stand physical contact with men, but still ends up having feelings for Kojou.
- Miss Conception: Such is Sayaka's utterly irrational fear and hatred of men that she thinks the most harmless of contact, such as wearing one's jacket or sitting next to Kojou, will get her pregnant.
- Ms. Fanservice / Statuesque Stunner: In the Anime, a great emphasis is placed on her tall stature and impressive rack.
- No-Sell: Koukarin has an in-built barrier that allows it to nullify almost anything.
- Schoolgirl Lesbians: Aspires to this toward Yukina. Even after falling for Kojou, she still loves her dearly and is very protective of her feelings.
- Sempai Kouhai: She is Yukina's sempai and former roommate.
- Thanks for the Mammaries: Kojou accidentally falls with his hands on her chest in episode 22.
- Tsundere: At first she is extremely dere for Yukina and extremely tsun for Kojou. After getting to know Kojou, she goes completely mush for him too, though still responds with tsun if he fails to pick up the obvious romantic signals she's sending him. La Folia later takes joy in revealing that Kojou is listed under Sayaka's favorite contacts on her phone.
- Voluntary Vampire Victim: The second girl to offer herself to Kojou to sate his blood thirst. Naturally, she is every Tsundere-ish about it—pretending that she doesn't like or want him to do it while she actually finds it just as pleasurable. Because of her love for Yukina, she also tries to keep it secret to avoid upsetting her.
- Zettai Ryouiki: Grade S if you count her side tails as twin tails.
A pure-blood / direct descendant vampire born from the lineage of the First Progenitor, the Lost Warlord. He knows Avrora Florestina, the original Fourth Progenitor, and implies that they were in love.
- The Ageless: As a vampire, he has lived far longer than most of the cast, yet still looks in his twenties.
- Ambadassador: He becomes the Ambassador in the Embassy of the Warlord's Dominion after the Nalakuvera incident.
- Ambiguously Evil: Vatler is so old and has seen so many things that he doesn't really think in a way comprehensible by mortals. This makes his actual morality impossible to read.
- Anti-Hero: Type 4 or 5. He does protect Itogami Island, but only from threats that he finds entertaining and he has no qualms using Familiars that literally eat his opponents alive.
- Ax-Crazy: Once he gets going, he goes absolutely batshit crazy.
- Badass Gay: By extension of being attracted to Kojou because he inherited the blood of Avrora Florestina.
- Badass in a Nice Suit: A white suit with a purple shirt and a black tie.
- Beam Spam: Can spam extremely powerful blasts of purple energy.
- The Beastmaster: All his Familiars seen so far have been extremely powerful dragons.
- The Beautiful Elite: Part of nobility? Check. Rich as hell and doesn't even bother to hide it? Check. Impeccable outfit in every single of his appeareances? Check. More aesthetically pleasing than most of the cast available? Double check.
- Bishōnen: Moreso than the rest of the male cast.
- Bi the Way: Was in love with Avrora Florestina, but has no qualms making passes at Kojou since he inherited Avrora's blood.
- Blood Knight: He engineered the entire Nalakuvera plot to fight the Nalakuvera as a way to amuse himself. Let us reiterate, he literally let a renowned terrorist group nick and activate a series of ancient Hindu superweapons for fun.
- His ultimate plan is to goad Kojou into becoming the "Complete Fourth Progenitor", the apex of his power, and then fight him to the death.
- Blue and Orange Morality: Christoph Gardos admits at one point that Vatler is so old that he is now reasoning in a way hard to understand for mortals.
- Cloudcuckoolander: His way of thinking is truly a puzzle to many. Even experienced people with a good head on their shoulders like Natsuki can't even speculate about what his next step is, only following behind and always keeping her guard up all the time.
Narrator: “La Folia and Vattler were watching, in complete and utter seriousness, a magical-girl show meant for children on an all-anime TV channel. They were having a very serious tactical discussion while watching girls in fluttering, miniskirted outfits doing battle with evildoers.”
- His unorthodox way of doing business is made apparent in the novel's fourth volume's first chapter, in which Vattler escorted La Folia to Itogami Airport on her way back to Aldegyr after the incident with Kanon. Choosing a magical girl show as a discussion topic with a princess from another country is... quite an unusual choice for a man of his status.
Narrator: “Even if it looked like a casual, peaceful discussion, what was unfolding between Vattler and the princess was actually a highstakes backroom negotiation between foreign powers.”
- And to think that he somehow managed to turn that said discussion into a legit backroom negotiation that is literally his main job description in the mean time...
- Cool Shades/Sinister Shades: Wears a pair at times.
- Cool Ship: The Oceanus Grave and, after it is sunk during the Nalakuvera arc, the Oceanus Grave II.
- Cryptic Conversation: Frequently has this with various characters, with him providing the Info Dump in vague sentences and the other character(s) becoming more annoyed as the conversation went on because of their inability to gain any useful information from the particularly one-sided conversation and/or embarassment if the said Info Dump is about them. All said with barely contained glee in his voice.
- Curb-Stomp Battle: Creams Yaze with a single blast of magic, and later dispatches two Prison Barrier inmates with little effort. Is on the receiving end when a possessed Nagisa trashes him with one of Avrora's Familiars, Alrescha Glacies.
- The Dreaded: The Meyer Sisters nearly shit themselves in terror when he encounters them.
- Fiction 500: Implied. Not only can he afford two extremely luxurious yachts without issue, he also has various princesses from countries close to The Warlord's Dominion as call girls.
- Flash Step: Demonstrated in "Warlord" arc, where he simply moved to another building to prepare for destroying the only land gateway to the Nalakuvera. We can only see him in a blur, when a second later he already arrived.
- Fusion Dance: Has the ability to fuse some of his familiars together.
- Healing Factor: As an extremely powerful vampire, this is a given.
- Info Dump: As the resident Mr. Exposition, this is a given. No matter how vague they are.
- Informed Ability: He's implied to be so ridiculously powerful that no character introduced so far is a match for him, which is why he's kept on the sidelines. Once he finally takes center stage in the Labyrinth of the Blue Witch arc, everyone is scared shitless of him, and we finally get to see why; He absolutely creams one of the extremely powerful Prison Barrier escapees so hard that Kojou has to stop him from having his Familiar eat her alive and immediately follows it by defeating a Dragon Slayer, who has a massive advantage against Vatler because of his Dragon familiars.
- In-Series Nickname: Natsuki refers to him as "Snake-Charmer" based on his multitude of snake-like Dragon familiars.
- Instant Awesome: Just Add Dragons!
- It Amused Me: Played straight since he himself stated that the reason he came to the island in the first place and helped Gardos get access to the Nalakuvera essentially was out of boredom, even though the 14th volume's revelation about his goal to start a war might make this a bit zig-zagged.
- Laughing Mad: Starts laughing maniacally upon realizing that part of Avrora's soul resides within Nagisa Akatsuki.
- Man in White: His usual suit is white, and he's morally ambiguous at best, trying to get rid of his boredom through various forms of entertainment.
- Manipulative Bastard: Not above using this by a mix of guilt-tripping and goading. Our pure main characters are extremely susceptible of this.
- Mister Exposition: Due to his extreme age and vast knowledge, he is often able to explain the many odd powers displayed in the show.
- Obfuscating Insanity: A possibility, although he does have his Ax-Crazy moments. When half of the casts in the series actually think that either he's interested romantically to Kojou or wants to fight him to death and eat him, and the other half think that he's so bored of his immortal life that he decided to try entertain himself by coming to Itogami Island, it's way easier for him to set his plan to start a warinto motion without hindrances, since most of the casts preferred to leave him alone when he's not doing something that could danger the island's civilians directly. It's not impossible for both to overlap, though.
- Our Dragons Are Different: His Familiars are the Eight Great Dragon Kings of Buddhism.
- Our Vampires Are Different: Bishōnen vampire with the power to summon and combine dragon Familiars.
- Perpetual Smiler: Vatler likes to wear a happy face most of the time, even if it's occasionally the wrong kind of happy face.
- Person of Mass Destruction: He claims that his Familiars will casually level the entire archipelago if Christoph Gardos makes an attempt on his life.
- Pretext for War: In volume 14 of the light novel, it's revealed that his very intention all along is to wage a war,even though the reason and the target has not been stated so far.
- Put on a Bus: Sayaka mentioned that he's gone to his home country for some 'jobs' in the OVA. Cue the last part of the episode showing him standing on cruising Oceanus Grave II.
- Really 700 Years Old: Vatler has been around since the foundation of the Warlord's Dominion an unknown amount of centuries in the past, yet he only looks a few years older than Kojou.
- Reclining Reigner: The ruler of a principality in the Warlord's Dominion, and was seen reclining on a sun lounge in his first appearance at the second volume of the light novel, complete with a glass of cassis in his hand.
- Red Baron: "The Duke of Ardeal".
- Red Eyes, Take Warning: While using his Familiars.
- Scary Shiny Sunglasses: When he gets fired up.
- Sharp-Dressed Man: Never seen without an impeccable suit.
- Single-Target Sexuality: He was in love with Avrora, the previous Fourth Progenitor. Since Kojou has inherited the position by consuming her, he has reported his affection on him. Much to Kojou's dismay, he doesn't appear to care if the new Fourth Progenitor is a man.
- Slasher Smile: When he gets worked up.
- Sociopathic Hero: For a given measure of "hero".
- Theme Naming: His Familiars are named after (and most likely are) the Eight Great Dragon Kings of Buddhism.
- Wham Line: Based on volume 14 of the light novel: "War, that's it."
- Wild Card: No one really knows his true affiliation and personal goals, he always change the sides where he put his support in. even the fans have given up trying to figure it.
- Wine Is Classy: Tends to fancy drinking it aboard his yacht, especially while expositing.
The leader of the Black Death Emperor Faction and a former soldier of the Lost Warlord's Dominion. He seeks to overthrow his former master through the use of the Nalakuvera.
- Arc Villain: The villain of the Nalakuvera arc.
- Beard of Evil: A goatee that blends in with his mane when transforming into a therianthrope.
- Beneath the Mask: When first introduced, he appears to be a rather composed, Affably Evil villain. This façade eventually crumbles as his Blood Knight tendencies become more apparent over the course of the arc.
- Blood Knight: Is pleasantly thrilled when fighting Yukina.
- Charles Atlas Superpower: He can create a biological barrier using Qigong.
- Hoist by His Own Petard: Kidnaps Asagi so that she can analyse and figure out the sound commands for the Nalakuvera's so that he can have a squad of virtually indestructible mechas on his side. Instead she manages to homebrew a command that causes the Nalakuveras to self-destruct.
- Knife Nut: His weapon of choice when fighting Yukina on board of Vatler's ship.
- Major Injury Underreaction: He barely even reacts to Himeragi cutting one of his hands of.
- Our Demons Are Different/Our Werebeasts Are Different: Becomes more muscled and sports a lion-like head upon transforming.
- Panthera Awesome: His demon form is very lion-like.
An ancient weapons system unearthed by the Black Death Emperor Faction under Christoph Gardos's command.
- Adaptive Ability: The reason why it is so powerful in the first place. It will instantly evolve and counteract according to the attacks used against it. This is first shown when Kirasaka chops one of it's legs off, only for the Nalakuvera to instantly deploy a repulsive field barrier to block her next attack not even 5 seconds later. As the fight with it drags on, it actually gains an adaptational immunity to Regulus Aurum.
- Beam Spam: Its main weapon, which fires powerful lasers.
- Cyber Cyclops: It has a single red "eye" that is also it's target indicator and main laser cannon.
- Deadly Disc: The Queen unit is armed with a twin-linked launcher of incredibly powerful discs that can even overpower Al-Nasl Minium.
- The Dreaded: It has supposedly destroyed countless civilizations in the past.
- Fantastic Nuke: Comparable to one. It has single-handedly wiped out an unknown number of ancient civilizations and according to Vatler, it can defeat a Progenitor.
- Force Field: As noted under Adaptive Ability, it comes up with the idea of a repulsive force field to block Kirasaka's Absurdly Sharp Blade before it even collides with the main body.
- Frickin' Laser Beams: "The Fire-Breathing Spear".
- Healing Factor: Another reason why it is so terrifying. Through the use of Elemental Conversion, the Nalakuvera can regenerate from being completely demolished in seconds.
- Hoist by His Own Petard: Asagi manages to analyse its sound command system and create a self-destruct command based on those sounds, which Himeragi broadcasts to all of the units by throwing Asagi's cell phone into the Queen.
- Humongous Mecha: Guesstimating based on it's relative size to human-sized characters, it's a little over 10 meters tall and 20 across.
- Nigh-Invulnerability: Through a combination of adaptive immunity to attacks, being incredibly tough to begin with and having an insanely powerful and near-instantaneous self-repair ability through the use of Elemental Conversion.
- Perpetual-Motion Monster: It has no need for any kind of energy source, is commanded entirely through a series of sound commands, can regenerate from debilitating damage in seconds and adapts to it's opponent's attacks to the point where it eventually becomes immune to it entirely. The only reason it didn't become completely unbeatable was that it was defeated by Asagi's homebrewed sound command before it could evolve out of control.
- Red Baron: "The Weapon of the Gods".
- Schizo Tech: It's far more advanced than any modern weaponry, yet is supposedly several thousand years old.
- Spider Tank: Pretty much describes its appearance to a T.
- Taken for Granite: Thanks to Asagi's analysis and implementation of a self-destruct command, all of the units, including the Queen, are disintegrated after turning into stone.
- We Have Reserves: After Kojou and Kirasaka manages to temporarily down the Nalakuvera, it turns out that there were another batch of units hiding on the Oceanus Grave, which immediately join the fight.
Characters introduced in "The Amphisbaena"
Nagisa's friend, Kanon is a girl who has a very kind and gentle heart. She has a tendency to call Kojou Onii-san.
Spoilers below (This is a double warning)
- Alliterative Name: Kanon Kanase.
- All Loving Heroine: To the degree where she is referred to as "The Middle-school Saint".
- Armor-Piercing Question: Drops a series of these on Kou in episode 22.
- Ascend to a Higher Plane of Existence: According to Kensei, once she reaches "Level 8", she will achieve Ascension and become an actual Angel.
- Because You Were Nice to Me: Kojou pays her a compliment over her dutiful care of the kittens inside the monastery, which prompts a grateful smile and thank you. It seems that this the first thing that sparks her feelings for him, because it's specifically wounding him in combat that causes her to Freak Out. After Kojou helps rescue her at the end of the arc, that seems to cement her interest in him, enough for her to directly tell him she wants to know what kind of panties he likes.
- Berserker Tears: Cries frequently when she is made into using her Angel Faux powers.
- Break the Cutie: Big things happen during the "Amphisbaena" arc, none of which are welcome to the poor girl.
- Brought Down to Normal: Is brought out of her Angel Faux state through the use of Himeragi's Schneesturm Wolfïn after Kojou removes her dimensional barrier with the help of his newly acquired Familiar, Al-Maisan Mercury.
- Covert Pervert: In episode 20, while she, Nagisa and Yukina are in a lingerie store and Kojou waits outside, she urges Kojou to come in with them so she can learn his taste in underwear.
- Devoted to You: She is the only girl in the series who almost never gets upset or self-conscious about Kojou. She does not show jealousy towards other girls, she does not play hard to get, and she does not reject his interest or advances. Case in point, when the time comes that she has to give her blood to Kojou, she is happy to do so without any reluctance.
- Dull Eyes of Unhappiness -> Blank White Eyes: After shooting Kojou through the heart with an energy blast as a sign of Despair Event Horizon and Heroic BSoD.
- Freak Out: Her seemingly killing Kojou causes her to go absolutely berserk before she freezes herself solid to stop her own rampage.
- Good Wings, Evil Wings: Three sets of angelic wings once she reaches Level 7, however they are definitely not good, which is made evident by the evil-looking eyes that manifest on them. Once her dimensional barrier is shattered, they become blood-red and covered in Tron Lines.
- Heroic Bastard: An illegitimate daughter of the father of the King of Aldegyr, technically making her La Folia's aunt.
- I'm Taking Her Home with Me!: When Nina is stuck as a Little Person, Kanon says this is perfect because she can take her home. Nina says, "Hey, don't treat me like I'm a pet!"
- Innocent Blue Eyes: They emphasize just how much of a saintly girl she is. Subverted when she's deployed for Kensei's experiments, where she flashes Creepy Blue Eyes coupled with Dull Eyes of Unhappiness.
- Innocent Fanservice Girl: In episode 13, when Kojou is warped into the bathroom she's taking a bath in because of the warp-space phenomenon happening all over Itogami Island. She calmly asks who it is before telling him that she and Astarte are using the bath first.
- Kindhearted Cat Lover: She takes care of dozens of kittens in an old burned down church.
- My Kung-Fu Is Stronger Than Yours: Yukina's Divine Vibrations are far inferior to the ones she generates, as while Yukina is merely a human generating those Vibrations, Kanon is an Angel Faux, close to the realm of the actual biblical God, and therefore radiates far more powerful Divine Vibrations.
- Mystical White Hair: The only other person to sport similar silk white hair is La Folia. This hints at them being blood-related.
- Nerves of Steel: Quickly decides to distract Kou Amatsuka and then calmly hits him with a series of Armor Piercing Questions.
- No-Sell: As an artificial Angel, she is of a higher dimension than most other beings, making her completely immune to their attacks. This causes Kojou's familiars to fly right through her without any effect. Kojou's Al-Maisan Mercury can nullify this by eating the dimensional border.
- Our Angels Are Different: She is an Angel Faux, an artificial angel who gains power by eating the spirit of other Angel Faux.
- Person of Mass Destruction: Kensei compares her to a natural disaster, and it's implied that she can grow even stronger if she devours the spirit of more Angel Faux.
- Power Gives You Wings: Specifically, power gives you more wings. With eyes on them. That shoot laser beams.
- Proper Tights with a Skirt: She's the only girl we've rocking this look so far. Combined with long sleeves underneath the fuku's short one's, she has the most "modest" costume of all the female regulars.
- Strong Family Resemblance: She looks like a younger version of her niece, La Folia. In fact, when La Folia was missing, all it took Kanon was to dress in her uniform (and put on a wig) to convincingly pass as her during the ensuing media conference.
- Talking the Monster to Death: What she uses to stall Kou.
- Tears of Blood: Sheds some after seemingly killing Kojou.
- Tragic Monster: Her rampages are clearly not something she herself desires, as evidenced by her frequently crying when her Angel Faux powers are activated.
- Tron Lines: Whenever her Angel Faux mode is activated, as well as on her wings when her dimensional barrier is eaten.
- Voluntary Vampire Victim: Joins the group of girls willing to "donate" their blood to Kojou while the two of them are trapped in a spell cast by Natsuki. Not only is it just as "erotic" as the other girls, she indicates that she'd be willing to do anything Kojou ever wanted of her without hesitation.
- Walking Spoiler: She is far more than what is suggested at the start of the "Amphisbaena" arc.
- Winged Humanoid: Of the artificial angel variety.
- Woobie, Destroyer of Worlds: She has been modified by her adoptive father / uncle in order to reach the state of ultimate lifeform, and is forced to murder and devour other similar artificial angels. Worst of all, she nearly kills Kojou, her big brother figure. Needless to say, her rampage at the arc's climax is justified.
La Folia Rihavein
The eldest princess of the Kingdom of Aldegyr, La Folia is seen to a quite cheerful young woman and quite friendly. Even though she just met Kojou, she seems to care for him as much as Yukina does for him.
- Almost Kiss: In the beginning of Episode 12 with an unconscious Kojou, only to be interrupted by Himeragi. She makes good on it and kisses him in front of all the other girls at the end of the same episode.
- Badass Adorable: As graceful as she is deadly, as charming as she is formidable.
- Bayonet Ya: Her magic gun also has a magical bayonet blade jutting out that's bigger than the gun itself.
- Bling of War: Her Curse Gun is extremely ornate with golden details.
- Calling Your Attacks: "Daughter of the gods that is within me... Protector of armies, age of the sword, bringer of victory and deliverer of death!"
- Cool Big Sis: Ironically to her *Aunt* Kanon, who although is her senior in social-standing, is three years her junior due to being a bastard conceived later by her grandfather.
- Every Proper Lady Should Curtsy: Curtsies when she formally introduces herself to Kojou and Yukina.
- Everything's Better with Princesses: From the moment she shows up, things start looking up for our heroes, and for the fanservice quota.
- Guile Heroine: When trapped in the ice with Yukina and Kojou, La Folia theorizes that the only way to heal the latter's wound is to sexually stimulate him and offer blood to awaken a familiar. Without further discussion, she immediately strips half-naked, straddles him, and prepares to kiss him but calls it "embarrassing". Yukina (partly acting on jealousy) stops her and offers herself instead, when La Folia backs down easily and smirks, she asks if this was La Folia's plan along. She gives a Non-Answer. When Yukina later falls asleep after the blood-drinking, La Folia is quick to offer herself again and it just so happens that the familiar that awakens needs two people's blood to work.
- The Gunslinger: Carries a "Curse Gun", which fires incredibly powerful magical bullets.
- Hotter and Sexier: She looks almost exactly like Kanase, except with a few extra inches of generous curves.
- Kicking Ass in All Her Finery: She's dressed in a very formal and decorative coat and skirt most scenes.
- Lady of War: Of the Guys Smash, Girls Shoot variety. Makes her no less badass, though.
- Laser Blade: Can recreate the Fake Holy Sword of the Völundr System seen in the prelude of Episode 9 with her bayonet by temporarily converting herself into a spirit.
- Light Is Good: Her bullets have an almost golden shine to them and she can use a Wave Motion Sword attack using the Völundr System that looks straight out of Fate/Stay Night.
- Living MacGuffin: A large amount of the magic Kanase Kensei knows requires a member of the Royal Blood of Aldegyr as a spiritual medium, which is why he wants his hands on La Folia.
- Mystical White Hair: Not to the extent of Kanon, but her bloodline has lots of magical talent.
- Nice Girl: She's cordial to Yukina, sisterly to Kanon, and very, very friendly to Kojou.
- Occult Blue Eyes: She can apply some sort of hypnosis through eye contact.
- The Ojou: Heir of a distant nation.
- Pop-Cultured Badass: She's a self-proclaimed fan of Japanese culture.
- Power Echoes: When using her Super Mode.
- Put on a Bus: At the end of the Labyrinth of the Blue Witch arc.
- Rapunzel Hair: It's waist-length.
- Royals Who Actually Do Something: When she found out her relative, Kanon, is in trouble, she leaves her country for Japan to rescue her.
- Shameless Fanservice Girl: Downplayed, but still present.
- She has little reaction to Kojou seeing her bathing naked.
- She does not hesitate in stripping, straddling or even kissing Kojou if it helps awaken his vampiric insticts. However, she says it's embarrassing to let Yukina watch.
- Spoiled Sweet: A very kind and friendly girl who happens to be a part of the royal line of Aldegyr.
- Super Mode: She can temporarily become a holy spirit and therefor use the Völundr System by chanting the words under Calling Your Attacks.
- Vapor Wear: She doesn't wear a bra, at any rate. Guesses are still out as to if this includes her Going Commando as well.
- Voluntary Vampire Victim: By far the most direct example in the series. She eagerly offered herself as Kojou's blood donor during their first battle together. Twice.
- What Beautiful Eyes!: Her eyes are drawn in a manner different to the rest of the eyes in the series that makes them indescribably beautiful.
The leader of Magus Craft. He is Kanon's adopted father whose younger sister is also Kanon's biological mother. He was a former royal court mage at the palace of Aldegyr. He had plans to make Kanon into a weapon to defeat the Fourth Progenitor.
- 11th-Hour Ranger: He is temporarily released so that he can assist the heroes in their pursuit of Yuuma in the Labyrinth of the Blue Witch arc.
- Alliterative Name: Like his adoptive daughter.
- Anti-Villain: Type 3; he wanted to make Kanon into a true Angel because he thought it would somehow bring her happiness, and because the arrival of a Fourth Progenitor, of which there are only supposed to be three of, marks the beginning of something bad, which Kanon's powers would be useful against.
- Arc Villain: Of the "Amphisbaena" arc.
- Court Mage: He used to be a royal court mage of the Kingdom of Aldegyr.
- Four Eyes, Zero Soul: Subverted, as he ultimately cares for Kanon's happiness, despite the dubious methods he uses to reach it.
- Graceful Loser: After Kanon is de-powered, he backs down and doesn't press the issue further.
- HeelFace Turn: After his defeat, he is put under Natsuki's supervision and assists the protagonists several times in the subsequent arcs.
- Lack of Empathy: Ultimately subverted, as he genuinely believed that he could make Kanon happy by letting her ascent to true angelhood.
- Mad Scientist: Turned his step-daughter / niece Kanon into an Angel Faux.
- Parental Substitute: After his little sister became pregnant with the child of La Folia's grandfather, he decided to take up responsibility and raise the child, Kanon, as his own.
- Pet the Dog: He genuinely cares about Kanon as if she were his own daughter.
- The Stoic: He tends to show cold scientific detachment in most scenes he's shown.
- Not So Stoic: When ranting on about Kanon's potential.
An employee of Magus Craft. She wields a spear containing the Familiar "Jabra".
- Absolute Cleavage: In her Spy Catsuit, she leaves the front completely unzipped down to her midriff.
- Alliterative Name: Beatrice Basler
- Arc Villain: Of the "Amphisbaena" arc, sharing the position with Kanase Kensei.
- Bitch in Sheep's Clothing: Plays the role of an innocent secretary to lure Kojou and Himeragi to an uninhabited island.
- Blade on a Stick: Jagura, a Familiar in the form of a whip spear.
- Dragon with an Agenda: At first she seems like a pawn to Kensei, but after he backs down, she attempts to claim the project for herself.
- Empathic Weapon/Living Weapon: She uses an "Intelligent Weapon", a Familiar in weapon form, in this case a whip spear. She claims that they aren't exactly a rarity, foreshadowing that they may appear again at a later point.
- Expendable Clones: She hopes to create clones of the Angel Faux using the blood of La Folia and then selling them for massive profits.
- Gainaxing: The only time her breasts stop bouncing is when she's standing completely still.
- Jerkass: Every other villain up until her introduction is downright pleasant in comparison to this bitch.
- Ms. Fanservice/Male Gaze: Every scene she's in contains at least 2 blatant fanservice shots of her.
- Only in It for the Money: As opposed to Kanase Kensei being seemingly in it for the sake of science.
- Red Eyes, Take Warning: When using Jagura.
- Sex Slave: Not herself, but she says that clones of La Folia and Kanon would go for lots of money even if they didn't have such strong magic power.
- Smug Snake: Perfectly pointed out by Himeragi; Without her whip she is a complete non-threat.
- Spam Attack: Her combat strategy boils down to pointing Jagura in the general direction of her opponent and just waiting for it to beat them to death with it's split whip attack.
- Spy Catsuit: What she wears to the final battle on the island.
- Vapor Wear: Clearly doesn't wear a bra.
Characters introduced in "Labyrinth of the Blue Witch"
A Childhood Friend of Kojou's who he used to play basketball with four years ago.
- Animated Armor: Le Bleu which is her Guardian of sorts. It actually belongs to Aya Tokoyogi, who proceeds to turn it against Yuuma and reclaim it as her own.
- Anti-Villain: In her arc, she's just trying to free her mother, as this is what she was programmed to do since her creation as a clone of the Witch of Notaria.
- Arc Villain: The main antagonist of the "Labyrinth of the Blue Witch" arc.
- Artificial Human: A clone of the Witch of Nortaria made specifically for breaking her out of the Prison Barrier.
- Bodyguard Betrayal: Her Guardian, Le Bleu, stabs her in the back after her mother Aya is released. Turns out it's actually Aya's Guardian. She gets him back later.
- Bokukko: Uses the pronoun boku when speaking, which does not help her tomboyish personality.
- Boyish Short Hair: To the point that when Kojou's harem sees an old picture, they're relieved to see what they think is a boy. That relief doesn't last long...
- Childhood Friend: To the Akatsuki siblings.
- Clones Are People, Too: From the moment he finds out about her history, the only thing Kojou is concerned about is Yuuma's well-being.
- The Dog Bites Back: Gives Kojou her blood so he can fight her mom.
- Forceful Kiss: To Kojou in The Stinger of episode 19.
- Genki Girl: Very spirited and lively, to the point that she throws herself into Kojou's arms when they reunite.
- Grand Theft Me: She can swap bodies with people by kissing them.
- HeelFace Turn: She was a reluctant Heel to begin with so after "Mommy Dearest" tosses her like so much garbage, she joins with Kojou and Co. to bring the bitch down.
- Hot Witch: Is one, and she dresses the part for the Festival.
- Lady Looks Like a Dude: When she was younger, which is the only time Kojou has pictures of her from. This makes Yaze and Asagi's jaws drop when she shows up with a sizable bust.
- Little Black Dress: In her witch cosplay, combined with Sexy Backless Outfit.
- Nice Girl: She really doesn't want to do what she was born to do, and actually chose to steal Kojou's body as the lesser of two evils. The original plan was to sacrifice 100,000 people, but his high magical power made that unnecessary.
- Put on a Bus: Has to go face punishment for what she did to the prison barrier, but says she'll see Kojou again.
- She's All Grown Up: In the picture Kojou has of her, she looks almost like a boy. Then she shows up in the Labyrinth of the Blue Witch arc with a massive increase in curves.
- Technicolor Eyes: Her eyes are two different shades of pink.
- Teleporters and Transporters/Villain Teleportation: Being the Blue Witch herself, she can manipulate space in the same manner as Natsuki, and sometimes uses her power to mess around with Kojou.
- Voluntary Vampire Victim: During the Labyrinth arc, she offers her blood to Kojou because of the special Anti-Magic qualities of her body. Like everyone, it has explicit sexual connotations.
- Walking Spoiler: For her arc, at least, seeing she's the antagonist until Aya takes the spot in the following arc.
Emma and Octavia Meyer
A pair of witches that are affiliated with the organization "The Library", squad "Philosophy". They work along with Yuuma Tokoyogi, but intend to use her for their own ends.
- Arc Villain: Share this position with Yuuma for the "Labyrinth of the Blue Witch", though it's clear they just don't measure up to her.
- Bare Your Midriff: Octavia, as part of her dancer-like outfit.
- Hot Witches: Although Octavia is closer to a bohemian dancer than anything.
- Nice Hat: Emma's hat is a traditional witch's.
- Oh, Crap!: When they realize they are fighting Vatler of all people.
- Power Floats: Due to their powers as Witches, they're able to levitate mid air.
- Purple Eyes: Octavia, and just like her sister, she's a feared criminal Witch.
- Red Baron: "The Witches of Ashdown", due to causing an incident in which a huge forest was destroyed overnight, aptly named the Ashdown Tragedy.
- Supernatural Gold Eyes: Emma has piercing yellow eyes, and is a Class 1 criminal Witch.
- Tome of Eldritch Lore: They use some that are borrowed from Yuuma, namely "Pre-Established Harmony".
- Weaksauce Weakness: Their Familiar is crippingly weak to fire, given it's a tree-like abomination.
- When Trees Attack: They possess a tree-like Familiar that uses its branches as tentacles.
- You Gotta Have Turquoise Hair: Emma, in contrast to her sister's black hair.
Characters introduced in "Fiesta for the Observers"
The Witch of Nortaria, as well as Yuuma's "mother" and leader of the organization "The Library".
- Abusive Parent: Dear god; she is completely uncaring of whether her clone Yuuma survives or not, despite having freed her from the Prison Barrier. Just to rub it in even further, she even rips Le Bleu away from Yuuma, something which is considered a serious injury for Witches.
- Animated Armor: Her Guardian, Le Ombre, which is Le Bleu's real identity.
- Anti-Magic: Using the Dark Oath Grimoire and Yukina, she plans to deprive the world of all supernatural abilities that are not her own.
- Arc Villain: Of "Fiesta for the Observers", although she had an influence in the previous arc.
- Barrier Warrior: She can deploy a field that repels and dispels Kojou's Al-Nasl Minium, though it's quickly shattered by Yukina's spear.
- Bond Villain Stupidity/Idiot Ball: Perhaps the most extreme example of this in the entire series: She kidnaps Yukina for no purpose other than to exposition as to how her Schneewaltzer actually works and Wangsting over how "witches are mocked and treated poorly" instead of taking out the heroes when she has them at her mercy, and then gives herself in to a Demon for a last-minute One-Winged Angel instead of surrendering despite being heavily outnumbered when she's given a chance to surrender.
- The Chessmaster: She baited everyone into believing that she needed Natsuki for her Anti-Magic plan, when she actually needed Himeragi and her Schneesturm Wolfïn. Completely averted by the next episode, however.
- Clipped-Wing Angel: When cornered and given a chance to surrender, she instead feeds her soul to a Demon to become one herself, although she's still swiftly defeated by a combined attack of Kojou's Regulus Aurum and Yukina's Schneesturm Wölfin.
- Dark Is Evil: Wears a sumptuous jet-black kimono and has a dark-themed Familiar. She's also an unrepenting dog-kicker of an Evil Sorceress.
- Establishing Character Moment: Violently ripping her daughter's Guardian from her body and calling her a useless object with a delighted smirk on her face.
- Familiar: Le Ombre, ripped straight from Yuuma.
- Hot Witch: Yuuma is her clone. We don't get to see much of Aya's assets in her kimono, but considering that, again, Yuuma is her clone...
- It's All About Me: To put it bluntly this woman cares about nothing besides herself, and has the gall to paint herself as a victim of society during her Motive Rant.
- Jerkass: The first thing she does upon her appearance? Impale Natsuki and her daughter, then go on about how Yuuma is a disposable piece of trash. Other Prison Barrier inmates aren't fond of her, either, and she even rebukes her own organization's members.
- Lack of Empathy: She nearly kills her own daughter in her introducing scene like it was the most casual thing in the world.
- Miko: In appearance at least.
- Purple Eyes: And by extension...
- Purple Is Powerful: Even with the prison barrier not completely taken down, she has enough power to match fighting the protagonists by herself. And her power is only bolstered by the Grimoire.
- Rapunzel Hair: It's knee-length.
- Smug Super: She really loves rubbing it in how superior she is to others. However, her plans end up completely foiled by her own negligence of Kojou.
- Summon Magic: She's able to conjure replica phantoms of the Meyer Sisters and the defeated inmates, although Kojou's Al-Nasl Minium mops the floor with all of them in a single attack.
- Time Master/Laser-Guided Amnesia: Grimore 014, which allows her to steal the very time someone has experienced, robbing them of their experience and memories from that time.
- Tome of Eldritch Lore: Her specialty is using these, being the rightful owner of the magic tomes used by Yuuma and the Meyer Sisters in the previous arc. She even attempts to turn the Ayami Academy building into her own Dark Oath Grimoire, given the original one was destroyed by Natsuki.
- Villain Teleportation: To the point of Teleport Spam.
Kojou and Nagisa's mother, as well as a certified doctor of magic.
- Absurdly Youthful Mother: She certainly doesn't look like she has a son in his mid-teens.
- Amazingly Embarrassing Parents: When she first runs into Kojou in episode 16, the first thing she does is scare him, Yukina, and Sayaka. Then she immediately starts asking the two girls which one of them is his girlfriend, and when she should be expecting grandbabies. Later she fondles Yuuma's breasts and claims it activates her powers.
- Badass Labcoat: She wears it while treating Yuuma. Suitably, she has a medical lab in her house.
- Bunny-Ears Lawyer: She's a certified magic doctor and a very skilled one at that... who dresses up with Halloween masks and gropes Yuuma's breasts.
- Idiot Hair: She has one single lock of hair sticking up on top of her head, and she's portrayed as kind of a doofus. (Although, there's clearly more to her than that.)
- I Want Grand Kids: She's very happy to see Kojou bring a bevy of beautiful babes to her door, and eagerly wants to know which of them is carrying her grandchild.
- Mama Bear: Has established a contract with Avrora Florestina to use one of Kojou's Familiars to keep Nagisa safe. The catch is that Avrora is inhabiting Nagisa.
- My Beloved Smother: When first met, she showers Kojou with affection and asks intrusive questions about his possible relationships to his female companion. Further, Kojou is worried that if she finds out he's a vampire, that she'd want to study or dissect him (although whether because he's a Progenitor or because he's her son is a different question.)
- Purple Eyes: Not very uncommon for this series, but important characters tend to have this eye color. As both a very knowledgeable medical mage, the protagonist's mother, and someone with a concealed past, it's hinted that she's far more important than we've seen thus far.
- Skinship Grope: Does this to Yuuma, despite the latter's injuries.
- You Gotta Have Dark-Blue Grey Hair: Like her son.
Tropes applicable to all the Inmates:
- Badass Crew: They are some of the most dangerous criminals in the world, so much so that no other prison than one sealed in a dimensional barrier was a safe place to hold them.
- The Dreaded: They're not sealed in a top security Prison Barrier for nothing.
- Heroic RRoD: If they become too weak or their lives are in real danger, the Prison Barrier system will instantly restrain them and dump them back in the prison.
- Quirky Miniboss Squad: Unwillingly for Tokoyogi Aya, who uses them as distractions to complete her own plan.
- Teeth-Clenched Teamwork: Some of them clearly don't enjoy the other's company, as Shtra demonstrates by immediately cutting open a fellow inmate to demonstrate the Prison Barrier system still being partially in effect.
- We Hardly Knew Ye: They get little screentime to showcase their powers before being defeated and sent back to the prison. Only Meiga Itogami, the former Lion King member, gets away scott-free, however.
A Kabulistani guerilla who implanted a fire spirit within his body, giving him power over flames. Arrested six years ago for attempted terrorism on Itogami Island.
- Alliterative Name: The same "ili" is repeated in the middle of both names.
- Bald of Evil: He's completely bald. And he's a psychopathic criminal in the same league as the other Prison Barrier inmates.
- Evil Old Folks: The oldest-looking inmate of the group that escaped.
- Implacable Man: Asagi tries to lose him in the sewers, but to no avail. First he melts an automatic doorway that was meant to block him. Then, after seemingly getting carried away by a reversed drainage channel, he shows up again by melting his way out of the sewers.
- Lean and Mean: He's quite emaciated and wrinkled compared to the rest of the cast.
- Playing with Fire: Implanted a fire spirit within his own body, something which Mogwai notes allowed him to kill his enemies more effectively.
- Smug Super: He slooowly chases Asagi through the drainage tunnels of the island, taking delight in the fact that he could cook both her and Natsuki at any time. Asagi evades him long enough to set up various traps, and then leads him to the most heavily-defended part of the island, where he promptly gets his ass handed to him by Astarte.
- This Cannot Be!: He's in utter disbelief when Astarte's Rhodactylos drains his spirit energy, which promply leaves him weakened enough for the Prison Barrier system to trigger itself.
- Wreathed in Flames: Is perpetually on fire the moment he activates his powers while pursuing Asagi and a de-powered Natsuki.
A tribe princess of the Third Progenitor's tribe who slaughtered a large amount of Demons in Hispania.
- Absolute Cleavage: Shamelessly flaunted.
- Alliterative Name: Gigliora Ghirardi.
- Badass Longcoat: The only part of her clothing that's even remotely covering.
- Bee Bee Gun/Bloody Murder: "Aguijón", which she summons through the use of blood.
- Combat Stilettos: As part of the Stripperific ensemble she's rocking.
- Eaten Alive: Narrowly avoids this at the hands of one of Vatler's more powerful Familiars when the Prison Barrier system re-enslaves her.
- Faux Affably Evil: She speaks in a sugary, sweet voice but once she starts fighting it's clear that this is a mask.
- Gag Boobs: Possibly the largest chest in the series thus far.
- Ms. Fanservice: She's the most under-dressed woman in the series as of the moment, and that's saying something. As Vatler shows her, though, having a lot of exposed skin and flimsy fabric turns out to not be a good move.
- Of Corsets Sexy: The ony other piece of clothing she wears underneath that longcoat besides her thong.
- Our Vampires Are Different: Like Kojou, Vatler and others, she's of the attractive, Familiar-wielding variety.
- Red Baron: "The Diva of Cuartas Theatre".
- Red Eyes, Take Warning: As her eyes are naturally red, they instead grow brighter when she uses her Familiars.
- Stripperiffic: Her outfit is very revealing.
- Thong of Shielding: Not surprisingly, it doesn't seem to do much for her when Vatler's familiars start biting her everywhere.
- Whip It Good: "Rosa Zombiemaker", a whip that enslaves everyone remotely close to it's impact. It even works on Familiars like Vatler's Sagara.
- The Worf Effect: Delivered to her with ease by Vatler after she defeats Astarte.
- You Gotta Have Dark Purple Hair
- Zettai Ryouiki: Grade A, minus the skirt.
A former combat mercenary frequently employed by the West European Church in the past.
- Badass Cape: He looks like a generic fantasy hero from somewhere between the seventies and the nineties.
- BFS: A gigantic one that greatly resembles the Dragon Slayer.
- Charles Atlas Superpower: Vatler all but spells out that his lineage's dragon hunting activities have given them absolutely inhuman strength and power.
- Church Militant: Whether or not he is actually a religious man is up in the air, but he did do the dirty work for the West European Church.
- Evil Sounds Deep: He has a very macho Badass Baritone, which he uses to sound menacing to his opponents.
- Expy: Of Guts, down to having almost the exact same looking weapon.
- Fatal Flaw: Vatler explains that due to his clan's talent as inhumanly strong Dragon Slayers, they are unable to recognize when they are truly outmatched by a greater opponent, as well as the strength dulling their wit so that they cannot outsmart them.
- Guttural Growler: He primarily attacks with physical force, so his growling and grunting tends to make him a much more physical presence.
- Heroic Lineage: A descendant of a clan of dragon slayers.
- Wrecked Weapon: His sword is riddled with cracks by the time Vatler is finished with him.
A murderous Deva who escaped from the Prison Barrier.
- Ax-Crazy: He gleefully cuts up a fellow inmate just to demonstrate the Prison Barrier's capabilities.
- Blow You Away: His wind powers are almost as powerful, if not equal to Kojou's Al-Nasl Minium.
- Dreadlock Warrior: Downplayed somewhat due to their short length.
- Elemental Punch: "Storm Breaker Axe", Which is powerful enough to be a serious bother even against Yukina's Schneesturm Wolfïn and Kirasaka's Koukarin.
- Hoist by His Own Petard: Kirasaka ends up using his wind with her darts to signal the lightning strikes that they cause.
- I Take Offense to That Last One!: During his battle with Kirasaka, she begins volleying insults at him and men in general, a list of flaws she ends with the fact that "they smell". Sthra only gets furious when she gets to the last one and responds with a "I DON'T SMELL!".
- Jerkass: Besides Tokoyogi Aya herself, he is by far the most unpleasant inmate.
- Multi-Armed and Dangerous: Though only when he gets serious.
- Semi-Divine/Physical God: He's part Tengu, meaning he descents from the godlike beings that ruled the world in the distant past and became worshiped as gods (It's pointed out that Yahweh, the Biblical god, is among them, as an example).
- Super Strength: Caused by combining the above trope with his wind powers.
A former attack mage of the Lion King Organization, held in the Prison Barrier for unknown reasons.
- Affably Evil: Is perpetually calm when addressing himself to Aya and Koyomi.
- Awesomeness by Analysis: He's able to deduce that Aya is fooling rest of the inmates by just by seeing her send them to capture a de-powered Natsuki, despite the fact that she stole Natsuki's memories, which contain the key to deactivating the Prison Barrier's system, thereby removing the need to even capture her.
- Bigger Bad: It turns out he was using Aya Tokoyogi's commotion as a means to get the Fangzahn back from the Demon District. He also shows up after the climax of "Empire of the Golden Dawn", presumably being the one who summoned the leyline-eating monster in order to sink Itogami Island; while that endeavour failed, he's still quick to note.
- Bishōnen: A standout case compared to the rest of the inmates.
- Blade on a Stick: After Aya's defeat, he retrieves the Fangzahn, a sealed weapon of the Lion King Organization, and a Flawed Prototype according to Koyomi.
- Bystander Syndrome: Decides to sit back and watch how Aya's plan will work out while the rest of the inmates are busy chasing down Natsuki, claiming it'll somehow benefit him as well.
- Cryptic Conversation: Appears after the climax of Episode 24 talking over the phone with Mogwai, contemplating about the leyline-eating dragon's defeat and musing that the Itogami Island (which he calls "capital of the corrupt") is going to prosper thanks to the Fourth Progenitor and his bride, not to mention the Priestess of Cain.
- Karma Houdini: By the end of the "Fiesta for the Observers" arc, he's the only Prison Barrier inmate remaining at large, being free of the system's shackles and having retrieved the Fangzahn. Not even Koyomi stops him.
- No-Sell: Is apparently unaffected by Aya's large-scale Anti-Magic.
- Peek-a-Bangs: His right eye is covered by his hair.
- Stoic Spectacles: Which go well with his reserved nature in contrast to the other inmates.
Kira Lebedev Voltisloa
One of Vatler's aides. He is a noble vampire from Warlord's Dominion.
- Dude Looks Like a Lady: He is by far the most feminine-looking male character in the series.
- Luminescent Blush: When greeting Kojou, no less.
- Nice Guy: At least he seems that way for now. He politely accepted and gave Kojou, Asagi, and de-powered Natsuki a small tour on Oceanus Grave II, and ensured their safety by guarding them through the emergency exit door when Broodt Dumblegraff attacked the ship.
- Perpetual Smiler: Always seen with a polite smile on his face in any situation so far.
- Put on a Bus: He only appeared in "Fiesta of the Observer" arc for one episode, and never seen again since. He came back at volume 10 of the light novel, though.
- Red Baron: "Vampire of the Phantom", due to his ability to disguise himself as practically anything, which proven to be quite useful when the holy beastmen betrayed Vatler in volume 10 of the light novel. He completely fooled them with that chopped up body.
- Red Oni, Blue Oni: He is the blue oni to Tobias' red oni with his calm and tranquil personality.
A vampire lord from Warlord's Dominion. He is one of Vatler's aides.
- Classy Cravat: Wears one at times, showing his status as a noble vampire from Warlord's Dominion.
- Crazy Jealous Guy: Downplayed somewhat, since he only expressed his jealously by his stare alone, never saying anything.
- Disapproving Look: Gives Kojou one while glaring at him from above the balcony.
- Put on a Bus: Only appeared in "Fiesta of the Observers" arc for a while. While he's still more fortunate than Kira who only appeared in one episode, he also didn't do much in each of his appeareances, making him easier to forget than Kira.
- Red Baron: "Vampire of the Evil Eye".
- What Does He See In Him: Seems like he couldn't understand why Vatler is so fixated on Kojou, and proceeds to taunt him regarding his uselessness as a Primogenitor when he appeared again on volume 10 of the light novel. It backfired.
Asagi's and Mogwai's co-worker at the Security Department of "Itogami Island Management Corporation" in Level B.
- Ascended Extra: While she only had a minor appearance on the arc she debuted in, she plays a bigger role in the Knight of Sinful God arc.
- Badass Adorable: She's a little girl who pilots a tank.
- Girlish Pigtails: Has this style.
- Intergenerational Friendship: With Asagi who is a few years her senior, and later with Ibris Velasisu.
- Little Miss Badass: She may be small, but pilots her personal tank.
- Purple Eyes
- School Swimsuit: Her primary outfit is one of this.
Characters introduced in "The Alchemist's Return"
An alchemist who seeks Wiseman's Blood for his own agenda. Was the student to Nina Adelard.
- Alchemy Is Magic: His entire schtick, being an Alchemist.
- Anti-Villain: Barely. He's definitely a Jerkass, but he was being used, and later on, he only stays a bad guy because he doesn't know what will happen to him if Wiseman is killed.
- Arc Villain: Of the "Alchemist's Return" arc, although his role ultimately gets dwarfed by Wiseman.
- Artificial Human: His current body is an artificial construct. As is he, actually.
- Ax-Crazy: To be putting it lightly.
- Become a Real Boy: His ultimate goal, something Kanon notes would never happen since he's a homunculus.
- Bishōnen: He has shoulder-length hair, which is tied into a sidetail with a ribbon; and "Kou" is a gender-neutral name.
- Blade Below the Shoulder: He often transforms his metal hand into this.
- Body Horror: Half of his body is missing and replaced with some kind of metal, which can turn into liquid state and change shapes.
- Complete Immortality: He seeks this in the form of the Wiseman's Blood, although the real reason was to make Wiseman turn him into a true human, which he never was.
- Faux Affably Evil: He's polite until he starts fighting, at which point he goes crazy.
- Go Mad from the Revelation: After Kanon's Tomato in the Mirror dialogue, he seems to lose his sanity a little. Even after he finds out the truth, he still fights, stating he knows nothing else, until Yukina frees him by vanquishing/vaporizing him.
- Go Out with a Smile: When Yukina runs him through with her spear, he finally realizes the meaning behind Nina's speech about being a human, letting a faint smile before getting vaporized.
- Healing Factor: He can use metal in his proximity to restore the left side of his body.
- Humanoid Abomination: As Nina notes, he's no longer human by the time of the series, being able to transform in liquid metal, as well create copies of himself in the same manner. As we later learn, he was never human.
- Knight of Cerebus: Some of his actions include trying to kidnap Kanon, putting Kensei Kanase in a coma and nearly killing Asagi for simply stumbling across while he was manipulating the Wiseman's Blood. He does all this in the episode he is introduced in.
- Kubrick Stare: Fond of doing this when he's up to something.
- Laughing Mad: Has a habit of breaking into this whenever he does something particularly sadistic or villainess.
- Man in White: His standard outfit is a white suit. It definitely makes him stand out as someone creepy.
- Motive Decay: Despite Nina revealing that he's just a homunculus created by Wiseman, he still goes on to defend Wiseman because it's the only thing he can do.
- Nice Hat: The red-checkered hat is his most distinctive feature to the point that the fandom (and Kojou) has nicknamed him "Checkers".
- Our Homunculi Are Different: Nina reveals that Kou was created by Wiseman and implanted with the desire to be the perfect human, hence his motivation.
- A Pupil of Mine, Until He Turned to Evil: Nina Adelard was his mentor until he became obsessed with his search for Wiseman's Blood.
- Red Eyes, Take Warning: His other most distinguishing trait, and the one that sells him as a hostile threat.
- Sharp-Dressed Man: Like we said, white suit and checkered hat.
- Tomato in the Mirror: Has this bomb dropped on him in episode 22, when Kanon tells him he was never a human being.
- Unwitting Pawn: To Wiseman, who soon reduces him into his right-hand man once he takes the center stage.
- Was Once a Man: He was once human, and wants to get his original body back. It's a lie. He never was.
An legendary alchemist who lived over two centuries ago, having reportedly created and subsequently used Wiseman's Blood to obtain an immortal body and unlimited magical power. She is Kou Amatsuka's master.
- Alchemy Is Magic: Although she doesn't see low-level techniques to be worthy of being called "alchemy".
- Bare Your Midriff: This is the outfit she takes in her true form.
- "Be Quiet!" Nudge: On the receiving one from Kojou, who slaps her face pretending to swat a mosquito as she's about to blow her cover.
- Buxom Is Better: Her original body is very well-endowed, so when she finally creates a new one for herself, she borrows Asagi's] appearance but increases the bust size. Natsuki teases Kojou about whether or not this is what he's into, and it's the first thing Yukina notices upon meeting her.
- Cool Old Lady: She doesn't look old due to being both essentially immortal and possessing the body of a teenage girl, but she speaks like a woman from another time, and says that "with age comes wisdom". She's nothing but cordial and polite, however.
- Doppelgänger: Temporarily borrows the form of Asagi, although modified to invoke Buxom Is Better.
- Emergency Transformation: Attaches her Hard Core to Asagi's body because she only had seconds to save the girl's life. She's not happy about doing it, but Kojou thanks her for saving his friend.
- First-Name Basis: After Kojou insists that she call him by his first name, she requests the same.
- Fish out of Temporal Water: Downplayed. But she doesn't speak much like a modern teenager.
- Godiva Hair: When she first appears in Asagi's body.
- Hair of Gold, Heart of Gold: She has blonde hair both in her original form and Asagi's, and she's one of the nicest and friendliest characters in the entire series.
- Half the Woman She Used to Be: Her artificial body is blown in half during the battle against Wiseman. But, since she's not human, she survives.
- Hime Cut: The hairstyle that both her liquid metal and real form take.
- I Am X, Son of Y: A variant, when she introduces herself as "The Scion of Hermes Trismegistus and perfector of the magnum opus, Nina Adelard of Palmia".
- Innocent Fanservice Girl: When she first shows up in Asagi's body, she steps out of Kojou's shower without a stitch of clothing on. Only after he repeatedly asks to get dressed does she finally put on a towel (which doesn't help much) and then borrow Kojou's clothes, and she expresses confusion both times.
- Killing in Self-Defense: When she first appears in liquid metal form, she brutally slaughters a dude from the inside out. However, said person had made it clear seconds earlier that he intended to destroy her soul so that he could take her power.
- Little Person: The size she's stuck in following the Alchemist arc.
- Older Than They Look: Her Immortality, Soul Jar, Shapeshifting, and possessing Asagi's body all make her look much younger than she actually is.
- Psychic Radar: She can sense that Kou's Wiseman's Blood is still active, indicating that he's still alive.
- Rapunzel Hair: Has long, billowing hair in both in her liquid metal form and Asagi's body.
- Really 700 Years Old: Astarte claims that Nina Adelard would be 270 years old if she were alive. Her soul is indeed still present, though she has to temporarily share Asagi's body before making a miniature of her own.
- Shapeshifter: Her liquid metal form can take a variety of shapes and appearances.
- Sharing a Body: With Asagi, and she's sorry about it.
- Soul Jar: The Hard Core which becomes embedded in Asagi's chest.
- Walking Spoiler: Once you know whose body she's in.
- Big Bad: Of the "Alchemist's Return" arc, supplanting Kou's role.
- Evil Cannot Comprehend Good: Wiseman claims to be a perfect being, and can't contemplate why he's facing so much resistance from Kojou and the others. Kojou calls him out on it, asking if anyone ever acknowledged him as perfect, or if he's ever used his powers for good. He also claims the former can't be perfect if he's defeated by an imperfect being such as himself.
- Evil Plan: His plan for resurrection which is basically to have Kou gather the necessary materials to facilitate his rebirth. Kou believes that he needs a powerful spirit medium to do this, but that isn't so. He can also do it with trace minerals in sea water.
- Gambit Roulette: There is no way he could have planned for Kanon to be on a boat headed for Tokyo at the exact moment Kou's plan failed. However, Nina speaks as if this eventuality was his plan all along.
- Generic Doomsday Villain: The least-developed Big Bad of any arc thus far. He shows up, tries to destroy the world, and gets defeated.
- Gold Makes Everything Shiny: Due to accumulating traces amounts of precious metals in the sea, his body is partly made of gold, to which Kojou can't help but call him "Blingy".
- In-Series Nickname: Kojou calls him "Blingy" due to his golden appearance.
- Kaiju: The form he takes when revived.
- Large Ham: He doesn't speak, he SHOUTS.
- Manipulative Bastard: Uses Kou Amatsuka in order to facilitate his return.
- Misanthrope Supreme: Despises humans because they are "imperfect" beings.
- Nigh-Invulnerability: His remade body is impervious to physical harm.
- Ultimate Life Form: Sees himself as this. Kojou instead hits him with a "The Reason You Suck" Speech stating that he's anything but.
- Un-person: Kojou defeats him by rewinding time back to a point where Wiseman didn't exist.
Characters introduced "Empire of the Golden Dawn"
Kojou and Yukina's daughter from 20 years in the future; she travels back to the past in episodes 23 and 24 to track down a powerful monster that threatens to sink Itogami Island.
- Adorkable: She has traits of this when she's talking to other characters and commenting on them in the past compared to how she's used to seeing them in her present day. Particularly with Asagi who she seems to swoon over to the point of approaching Les Yay, and with Yaze, who will seemingly start to suffer from baldness due to his use of certain hair products. She also slams herself accidentally into a glass door, not being used to non-automated ones.
- Blade on a Stick: She wields Hasta Aurum, which resembles a golden Sekkarou. She also summons it in a similar manner to a Familiar, implying it's sentient.
- But Now I Must Go: After completing her mission, she goes back to the future, but not before telling Kojou and Yukina that they'll meet her again someday.
- Cursed with Awesome: Much like Kojou, she also has the "curse" of immortality. Hence why she shrugs off that seemingly fatal attack moments earlier by the monster she was chasing after.
- Fish out of Temporal Water: She drops several hints that she's not from the present time during episode 23.
- She's not used to normal glass doors, thinking they'd be automated.
- She's astounded by the appearance of several main characters, hilariously letting out that Yaze would turn fat and bald, telling Natsuki that she hasn't grown an inch (complete with "Natsuki-chan"), then calling Nagisa and Asagi "aunt" note and "Doc" respectively, commenting on how they all look so young.
- Gainaxing: Her breasts bounce back and forth during her appearances, something which doesn't sit right with Yukina.
- Get a Hold of Yourself, Man!: When Yukina angsts over not being able to protect Kojou anymore due to the broken Sekkarou, Reina snaps back that she should do what she feels is right; not as a Sword Shaman of the Lion King Organisation, but as a girl.
- Kid from the Future: She went back in time to track down and destroy a bio-weapon of sorts that drains mana from the ley-lines connecting Itogami Island. That, and to take a look at what her parents looked like in their younger days.
- Locked Out of the Loop: Aside from what she's already said to other characters, she was on the verge of telling Kojou who she was, until Natsuki forces her not to reveal that.
- Naked on Arrival: She travels into the past in a similar manner to the Terminator, complete with landing naked next to Yukina, quickly proceeding to knock the latter unconscious and steal her clothes.
- Nosebleed: Another conspicuous attribute that she inherited from Kojou, although it happened when Reina was contemplating Asagi's looks.
- Our Vampires Are Different: As Kojou's daughter, she inherited the powers and abilities of a Progenitor, but since her mother is a human, she's more of a half-vampire.
- Red Eyes, Take Warning: Just like Kojou, her eyes turn red when she activates her Progenitor powers, willingly or accidentally (as shown by her arousal at Asagi's looks).
- "Silly Me" Gesture: After she returns to the future, she says that she misses her Disappeared Dad, implying something terrible happened. She's immediately called out on it by the other lady, saying that she talked to him that morning. Reina then does this gesture, indicating she was joking for dramatic effect.
- Strong Family Resemblance: Takes after her mother appearance-wise, but with some slight differences; she has Kojou's blue eyes, her skin tone is lighter, and her hair is straight-black instead of dark brown. She's also a little older, taller, and more (ahem) "developed" than her mother.
- Walking Spoiler: Her physical traits and abilities are a dead ringer for the fact that she's the protagonists' daughter from the future, giving a literal glimpse at the empire Kojou will eventually build, in addition to spelling out a Foregone Conclusion for the main Will They or Won't They? of the series.
Kojou's daughter who's responsible for sending Reina 20 years back to the past. It is stated in the novel's short story that she's Kojou's and Asagi's daughter, making her and Reina half-sisters.
- Last Episode, New Character: A more extreme example than Reina, since she only makes her physical appearance in Episode 24's epilogue, despite providing Reina with intel earlier on.
- Mission Control: What her role is in the "Golden Dawn" arc, assisting Reina from the future by giving her intel on how to proceed forward with her mission (presumably to avoid paradoxes).
- Walking Spoiler: Par for the course for future child characters, although in her case she marks the fact that Kojou will have more than one wife.
Characters introduced in "The Kingdom of Valkyria"
The current king of Aldegyr and La Folia's father.
- An Axe to Grind: His weapon of choice, befitting his gallant stature.
- Badass Beard: He has a well-groomed beard, and enough strength to send Yukina flying even when she blocks his axe.
- Berserk Button: Anything that involves threatening his family in general, his daughter and Kanon in particular.
- Big Brother Instinct: Unlike most royals in fiction, Lucas adores his newfound sister Kanon in-spite of the fact that she is a bastard, and instead of treating her as a threat to his throne, loves and cares for her like she is also his daughter.
- Culture Equals Costume: Wore a complete viking costume set at a foreign country in the middle of the day. No wonder the cafe waiters are scared shitless.
- The Good King: Prioritizes the party guests' safety before his own when uninvited guests crashed the party.
- Heroic Build: He's a good two heads taller than Kojou and built like a tank on legs.
- Papa Wolf: The reason he plans to marry La Folia off is because of his worry about his daughter's relationship with the Fourth Primogenitor. When he met Kojou at Itogami Island, he openly showed his dislike for him, which only intensifies when discovers that Kanon and the other girls are into him as well.
- Supernatural Gold Eyes: And they're just as striking as his daughter's blue ones.
Current queen of Aldegyr and La Folia's mother. She is also Kanon's half-sister by virtue of her being the daughter of the former king.
- Absurdly Youthful Mother: Can easily be mistaken to be her daughter's big sister.
- Cool Big Sis: Polifonia, unlike most royals in fiction, adores her newfound half-sister in-spite of her being a bastard; Though her bond with Kanon closer resembles that of a loving mother-and-daughter relationship than sisters proper, as she is younger than her daughter
- Let Her Grow Up, Dear: Unlike her husband, Polifonia is delighted that La Fiola and Kanon found love in Kojou; not only does she encourage both of them to pursue him romantically and sexually purusue him, she even literally drags her husband away (with that winning smile on her face) whenever he gets too "enthusiastic" in keeping his daughter and newfound sister "pure."
- Open-Minded Parent: Compared to her husband, she doesn't really mind her daughter's interest in Kojou and in fact basically encourages it.
- Strong Family Resemblance: It's easy to see where La Folia gets her looks from, as well as the fact that she and her half-sister Kanon resemble each other to begin with.
A member of the Free Terrorists and the main antagonist for the Kingdom of Valkyria OVA.
- Beauty Mark: On the left side of her mouth.
- Berserk Button: Doesn't take too kindly when La Folia calls her "old hag".
- Canon Immigrant: She was originally an anime only character for the OVA. However, she was later added into Volume 18 of the light novel.
- Decoy Damsel: Pretends to be in danger to get close enough to Kojou to use her pheromones to take control of him.
- Living Aphrodisiac: Much like a civet, she can use pheromones to control others, and is strong enough to manipulate Kojou, who normally is immune to mind-controlling spells.
- Supernatural Gold Eyes: Which indicate she's a Beastmen.
- You Gotta Have Blue Hair: Her's is violet.
Characters introduced in "Black Sword Shaman"
A mysterious girl that Kojou meets while at a resort. She's actually a succubus with an alternate personality named Riru and the key to control the Magical Beast Leviathan.
- Accidental Proposal: After Kojou saves her and promises she'll have a happy life, she now wishes to marry him.Yume: You promised you'd keep me happy forever, right? I'll do my best!Kojou: I didn't mean it that way!
- Barrier Maiden: She's the key to control the Leviathan.
- Death Seeker: The burden of holding Lilith's legacy and her parents and friends ending in a coma because of her powers made her want to perish at the Leviathan, where Lilith's soul can't reincarnate. Kojou talks her out of this.
- Horny Devils: Her succubus powers can make women(those around Kojou), act on their feelings of jealousy.
- Human Sacrifice: She was intended as sacrifice for the Leviathan. She actually wanted to be sacrificed to the Leviathan so people around her wouldn't suffer. Kojou manages to talk her out of it.
- Our Demons Are Different: She can sprout wings and a tail. Also the consciousness of Lilith has been passed down through her bloodline for generations.
- Token Mini-Moe: She's the youngest girl interested in Kojou. His friends believe he's a paedophile, much to his bemusement.
A sword priestess working for an opposite organization to the Lion King's Organization. She was hired to recover Yume.
- Alliterative Name: Kiriha Kisaki.
- Antagonist Title: She's the eponymous Black Sword Shaman of the story arc.
- Awesome by Analysis: She deduced Sayaka's powers pretty easily.
- Blade on a Stick: Like Yukina she wields a magical spear, but hers can copy the abilities of others.
- Blood Knight: Despite her initially calm demeanor, she relishes on combat, and even gets excited when Yukina draws blood from her.
- Graceful Loser: She took her defeat at Sayaka's hands during their second face off pretty well.
- It Amused Me: Her apparent reason to help Kojou and Yukina leave Itojima Island after Nagisa.
- Kung-Fu Wizard: Even without her spear she's incredibly skilled at close quarters.
- Purple Eyes
- Rapunzel Hair: It reaches her waist.
- Rivals Team Up: She fights alongside Yukina against Natsuki (who tried to prevent them from leaving the island).
- The Tease: Loves flaunting her charms to fluster Kojou.
Characters introduced in "Night Lord of the Blazing Light / Fourth Progenitor on the Run"
Kojou and Nagisa's father, as well as Mimori's ex-husband. An archaeologist who also has met Natsuki. He asked Natsuki to look after Kojou and Nagisa's after their incident, traveling the world to find a "cure" for his children.
- Adventurer Archaeologist
- Dirty Old Man: Very much implied. He revels in the thought of Yukina "stalking" her son when he first meets her and is later shown hanging out in a strip bar when Kojou, Yukina, and Asagi are tracking his and Nagisa's whereabouts on the mainland.
- Disappeared Dad: Since divorcing Mimori he hasn't seen his children much.
- Fights Like a Normal: He prefers to use firearms stored in his Hyperspace Arsenal.
- Hero of Another Story: He gets an entire episode dedicated to him, to demonstrate that he's just as capable as his son, in many ways. We also get several hints of what kinds of adventures he's gotten into past and present, but for the most part, we don't the pleasure of seeing them onscreen.
- Hyperspace Arsenal: The ability he gained at some ruins.
- Multicolored Hair: Has black hair with silver tips.
- Papa Wolf: Despite being away most of the time, he's very protective of his children.
- Strong Family Resemblance: He's essentially what Kojou would look like if he was older and had darker hair along with a Perma-Stubble.
Characters introduced in "Knight of Sinful God"
Gajou's mother and Kojou and Nagisa's grandmother.
A member of the Lion King Organization sent to break the seal of Kannawako.
- Miss Fanservice
- Mystical White Hair: Its pale blonde but fits regardless.
- Naked First Impression: Nagisa first meets her completely naked.
- Purple Is Powerful: She has Purple Eyes and wears a purple kimono.
- Unwitting Pawn: She was used by the Holy War faction to break the seal of Kannawako and use Glenda's powers for their own purposes. She's none too pleased when she finds out.
A War Dancer from the Lion King Organization.
- Archer Archetype
- Generation Xerox: In an odd way, she worked alongside Gajou in a very similar way Kojou and Sayaka did.
- Intergenerational Friendship: With Gajou, who is old enough to be her father.
- Those Two Girls: At first she was this with Yuiri.
- Tsundere: Similar to Sayaka, she's a bit short tempered, but can be kind.
Another Sword-Shaman from the Lion King Organization.
One of the Second Primogenitor's many children, who unexpectedly arrived to Kannawa Lake.
- Familiar: His takes the form of a giant cobra.
- Lonely Rich Kid: While he is certainly way older than what this trope usually requires, his child like appearance, fearsome reputation, and apparent wonder in some mundane things have somehow make him look like one: a person from high social standing that almost has no companions that he could interact leisurely with. His interactions with Asagi and Didier also make him look like more of a lonely rich, sheltered kid than the hundred-years-old vampire prince he really is.Ibris: (To Asagi and Didier) Not a lot of people can speak leisurely with me like this.
- Odd Friendship: Strikes one with Asagi and Didier, that might also double as Intergenerational Friendship.
- Power Gives You Wings: He can summon wings from his familiars.
- Really 700 Years Old: Looks like a young boy, but as a prince from the Second Primogenitor's dominion, he must be very old.
- Royals Who Actually Do Something: He went to Japan in order to investigate the Fourth Primogenitor and the rise of Holy War faction on behalf of his dominion.
- Warrior Prince: As a prince, he plays an active role in hunting down rebels for the Second Primogenitor's dominion, developing quite a fearsome reputation similar to Vatler. This active role in front line might explain his Blood Knight tendencies a bit.
A young girl that was sealed at Kannawa Lake that becomes attached to Yuiri. She's actually a dragon that can take human form.
The previous Fourth Progenitor, who somehow passed her powers unto Kojou three months ago.
- Badass Adorable: She was a girl in middle school, going by her uniform being the same as Himeragi's.
- Battle Amongst the Flames: She dies in Kojou's arms in a field of fire.
- Because You Were Nice to Me: Both Avrora and one of her "sisters" Enatos turned against "Root" Avrora because Koujou treated them to ice cream (among other things).
- Deader Than Dead/Critical Existence Failure: After giving her powers to Kojou, she disintegrates.
- Death by Origin Story: If she hadn't died, we wouldn't have the series.
- Face Framed in Shadow: Almost every flashback of her is marked with this.
- I Cannot Self-Terminate: While it was Koujou's hand wielding the weapon, she was using her connection to him as her Blood Vassal to make him do it. Possibly because she was incapable of actually holding one of the few weapons capable of killing her.
- An Ice Person: This seems to be her favourite power, as one of her Familiars, Alrescha Glacies, is often summoned whenever Avrora takes control of Nagisa's body, even reducing Vatler to a bloody pulp with it. Taken to the next level when she freezes the sea in order to halt Wiseman's rampage.
- Impaled with Extreme Prejudice: Shot through the torso with a crossbow bolt, seemingly courtesy of Kojou.
- Implied Love Interest: Kojou's extreme reaction to her death may imply that he had feelings for her.
- The Lost Lenore: To Kojou, and apparently Vatler, who decides to take his affections on Kojou instead.
- Posthumous Character: Thus far, we've only seen her in flashbacks and a backup body.
- Rapunzel Hair: She had incredibly long blonde hair that almost reached her feet.
- Red Baron: "Kaleid Blood".
- Sealed Inside a Person-Shaped Can: Twice over. Was the vessel for Alrescha Glacies, and now her consciousness (and some of her power) is sealed inside Nagisa
- Shrouded in Myth: All we know about her comes from a flashback and some vague comments from Vatler.
- Take Up My Sword: Passed on her powers to Kojou, claiming that she had "granted his wish".
- World's Strongest Man: She is the reason the Fourth Progenitor holds the title of "The World's Strongest Vampire".
- You Are Number 6: Also known as Dodekatos, the Twelfth Kaleid Blood.
One of the three leaders of the Lion King Organization.
- Ambiguously Evil: She tasks Yukina and Motoki Yaze with watching over Kojou and suppressing him if his vampiric powers go out of control, given the Lion King's mission seems to be preserving the balance between the humans and demons.
- Bystander Syndrome: Decides to do nothing with Meiga Itogami as he leaves with the Fangzahn, claiming that no real harm to the Lion King Organization will come out of it.
- Everyone Has Standards: Even she seems somewhat disgusted with Himeragi and Kirasaka being used as nothing more than pawns to be Kojou's "mates".
- The Faceless: Up until the "Fiesta for the Observers" arc.
- Girlish Pigtails: Tied as sidetails that hang down her collar.
- Improbable Age: She's a middle-school student like Himeragi, yet is her direct superior in the Lion King Organization.
- Paper Master: As her name implies, she can create Shikigami animals that she can use to communicate over long distances.
- Red Baron: "Paper Noise", due to the elusive surveillance shikigamis she uses.
- The Stoic: Though this may simply be related to how Kana Ueda acts.