All spoilers regarding the first four story arcs (volumes 1-20) are unmarked. Examples pertaining to the fifth story arc and Shin High School D×D can be spoiler tagged if necessary.
This page details the various supporting characters outside of the Occult Research Club in High School DXD.
Kuoh Academy Students
Matsuda and Motohama
- Matsuda voiced by: Yasuaki Takumi (Japanese), Tyson Rinehart (English)Motohama voiced by: Takuro Nakakuni (Japanese), Ruben Tadeo Garcia (English, 2013-2015), Stephen Sanders (English, 2018-present)
Matsuda and Motohama are Issei's friends at Kuou Academy. They are just as perverted as he is.
- Butt-Monkey: In every scene they appear like two losers who are not safe from the world's abuse as opposed to Issei. Examples include being beaten up by girls and being chased around.
- Green-Eyed Monster: They are both jealous of Issei's relationship with the girls of the Occult Research Club to the point that they beat him up for it.
- Laser-Guided Amnesia: After Yuuma reveals herself as a Fallen Angel and kills Issei, she erases their memories of them.
- Only One Name: Their given names are unknown.
- The Peeping Tom: The girls of the Kendo club are often subjected to Issei, Matsuda, and Motohama's lecherous peeping.
- Pretty Fly for a White Guy: This is how Matsuda talks in the English dub.
- Satellite Character: Their role is pretty much exclusively to discuss perverted stuff with Issei or complain about his success with pretty girls.
- Scary Shiny Glasses: Motohama wears one and uses it to measure a girl's B-W-H.
- Shoo Out the Clowns: Whenever the Occult Research Club gets into battle, Matsuda and Motohama are pushed to the side.
- Tears of Blood: Their reaction to Issei when he tells them he is dating Rias in Volume 22.
- Those Two Guys: They always show up together.
- Throw the Dog a Bone: As of Shin High School D×D, Matsuda has a new girlfriend named Hase.
- Took a Level in Jerkass: They become jerks because of Issei hanging around the Occult Club girls, spreading completely fake rumors about Issei and each of the girls. They even made one about Issei and Kiba being a gay couple, something that would later be the inspiration for an in-universe doujin about the two made by the Academy's manga club.
- With Friends Like These...: You have to wonder why Issei is still friends with them considering all the rumors they spread about him and constantly beating on him.
- Wrestler in All of Us: Both of them did a combined Brain Buster on Issei when he introduced them to Mil-tan and friends.
Murayama and Katase
- Murayama voiced by: Yui Ogura (Japanese), Haley Esposito (English)Katase voiced by: Kaori Ishihara (Japanese), Mary Morgan (English)
Murayama and Katase are of Issei's classmates who are members of Kuoh Academy's girl's kendo club.
- Ascended Extras: Their names were only mentioned once in the first light novel, but they get a proper introduction in the anime.
- Curtains Match the Window: Both of them.
- Hair Decorations: Katase wears a white headband.
- Reused Character Design: Murayama looks a lot like a younger version of Issei's mom with pigtails.
- Those Two Girls: They are always seen together.
- Voiced by: Haruka Yamazaki (Japanese) and Alexia Sabanbeard (English)
Aika Kiryu is Asia Argento's friend and is also Issei Hyoudou's classmate.
- Adaptational Curves: In the light novels, her chest is nearly the same size as Koneko's. In the manga, however, they are a full cup size bigger.
- Distaff Counterpart: To Motohama. She wears spectacles, and like Motohama, she can calculate a male's "manhood" size just by looking.
- The Gadfly: Trolls Issei so badly, it's hilarious.
- Girlish Pigtails: Braided variant.
- Lovable Sex Maniac: One of her most well-known traits is her habit of giving lewd advice to Asia, such as telling her about "skinship" and encouraging her to try it with Issei in the bathroom and warning her not to dilly-dally in making a move on Issei before the other girls could get him.
- Mundane Utility: She's begun learning magic from Lavinia Reni, with the intention of mastering love-centered astrology in order to make a fortune in the matchmaking scene.
- Scary Shiny Glasses: Reveals she has one and can measure a guy's nether region which scares Issei!
- Secret Keeper:
- Knows Asia has a crush on Issei and is willing to tell him; however, Asia always shuts her up.
- She's recently learned about the existence of the supernatural when she takes one of the summoning circle fliers and summons Xenovia from it.
- Shipper on Deck: For Asia and Issei.
- Shoo Out the Clowns: She is pushed to the side whenever something serious happens like Kokabiel and the Khaos Brigade attacking Kuoh Academy.
- Skinship Grope: With Asia after observing that she grew up during summer vacation.
- Took a Level in Badass: Has begun training in magic from none other than Lavinia Reni.
- Waistcoat of Style: In the light novels, she wears a waistcoat along with her uniform.
- Zettai Ryouiki: Grade A in the manga.
- The Beastmaster: She's a beastmaster.
- Mega Twintails: She has large twintails.
- Ojou Ringlets: She has two small ones.
- Passionate Sports Girl: Captain of the tennis club and teaches all the creatures she has tamed how to play as well.
- Romantic False Lead: Although she and Issei have quite a bit of ship tease, it never really goes anywhere, even after she asks Rias to use him as The Beard to avoid an Arranged Marriage.
- Voiced by: Tsuyoshi Aoki (Japanese), Ricco Fajardo (English)
Mr. Morisawa is Issei Hyoudou's first customer who's also an Otaku.
- Voiced by: Kenta Miyake (Japanese), Chris Rager (English)
Mil-tan is one of Issei Hyoudou's first customers and is cosplaying as a Magical Girl but is also a guy.
- Ambiguously Human: Aside from being able to completely No-Sell Leviathan's sedation magic, and apparently, he's been to alternate universes in his quest to become a genuine Magical Girl.
- Chekhov's Gunman: Whatever he is, he is a special case. Considering he nullifies Leviathan's hypnosis magic and beats the crap out of wizards with nothing but his fists...
- Creepy Crossdresser: Well what do you call someone who's big, well built, and is cosplaying as a magical girl?
- Tragic Dream: Played for laughs. He wants to be a genuine magical girl, even supposedly going to alternate dimensions, and Ise's first contract with him was attempting to get a devil who could do it.
- Verbal Tic: Ends his sentences with "nyo". Even Issei says it when he was first introduced (though it's more like a Big "NO!" with how he said it).
Susan is one of Issei Hyoudou's first customers who first appeared in the Volume 8 side stories (Episode 6 in the anime). An exchange student who's an avid fan of Japan back in the old days.
- The Faceless: She always keeps her face covered by a samurai's helmet.
- Love at First Punch: Shoots an arrow with a love letter to her future lover who's wearing a Knight in Shining Armor. Needless to say, Issei was not amused.
- Occidental Otaku: Has a lot of samurai stuff in her room. She even dresses like one.
- Samus Is a Girl: She may look like a knight on the outside, but she's a young girl on the inside.
One of the human world's native inhabitants, vampires are a group of species that use humans as a source of food and can manipulate shadows and darkness. Despite dismissing humans, angels, and devils as primitive races, the vampires boast a proud warrior culture.
- Achilles' Heel: Their weaknesses are sunlight, holy water, crosses, and garlic. These are mitigated, if not removed outright, in half-vampires.
- Broken Pedestal: Elmenhilde's cousin, brother, and male kin become one to her when they betray her and the Carmilla Faction.
- Cannibalism Superpower: They can copy the abilities of those whose blood they consume.
- Casts No Shadow: Pure-blooded vampires don't have any shadow.
- Enemy Mine: The climax of volume 16 forces the vampires to put aside its prejudices to help end the vampire civil war. As of volume 21, the remaining vampires joined the DxD alliance.
- Fantastic Racism: Originally, the pure-blooded vampires and anyone who isn't pure-blooded (such as the Three Factions, half-vampires and humans) didn't like each other very much. They view humans as their true nature for their source of food. In the final days of the vampire civil war, however, the vampires, humans and the Three Factions are able to put aside their differences and declare peace. The fifth story arc and Shin High School D×D both show that relations between the vampires and everyone else have improved since the formation of the DxD alliance.
- Half-Breed Discrimination: In addition to their racism towards those that are not pure-blooded vampires, they look down on those who have half-human or half-devil heritage, especially Gasper and Valerie.
- Hellish Pupils: Their distinctive red eyes are paired with slitted pupils, a trait still seen in half-vampires like Gasper and Valerie.
- It's All About Me: The pure-blooded vampires care about themselves. Well, until the aftermath of Rizevim's attack on the Tepes and Carmilla factions, at least...
- Medieval Stasis: Downplayed; the high-ranking pure-blooded vampires have outfits and mansions straight out of the middle ages, but the rest of their society lives in more modern houses.
- Missing Reflection: Pure-blooded vampires have no reflections on mirrors.
- Our Vampires Are Different: They follow many of the common rules, such as needing to be invited before entering someones home, and a lack of reflection or shadow.
- Red Eyes, Take Warning: They have red eyes and can be merciless in combat.
- Super Smoke: They can control fog to cover their residence so as to block out sunlight.
- Undeathly Pallor: Pure-blooded vampires' skin is so pale that they don't look alive.
- Voluntary Shapeshifting: Vampires can turn into a flock of bats or change part of their bodies into insects or bats.
- Weakened by the Light: Sunlight isnt lethal to pure-bloods, but it severely weakens them, so they cover their territory in perpetual fog and wear heavy clothing outside it.
- Weather Manipulation: Vampires can use fog to create barriers or search for enemies.
Lord Vladi is the head of the House of Vladi, and father of Gasper Vladi. He's also a member of the Tepes Vampire Faction.
- All of the Other Reindeer: He, and the rest of the Vladi house, were fearful of Gasper due to his hidden-power, later revealed to be a fragment of the evil Irish god, Balor, having caused the mother of the Vladi house to die of shock after seeing Gasper's true form.
- Badass in Distress: Despite being the head of House Vladi, he is confined in Tepes castle during Marius' coup.
- "It" Is Dehumanizing: He only refers to Gasper as "that", out of fear toward his powers.
- Parental Neglect: He refused to properly take care of Gasper due to fearing the power within his son.
- See his entry on the Occult Research Club page.
- The Bus Came Back: She's completely absent when she suffers a Convenient Coma in volume 16 and doesn't appear until volume 19, where she is given a fragment of the Grail.
- Childhood Friend: She befriended Gasper as a child, bonding under the Half-Breed Discrimination they both faced. She's also responsible for his crossdressing.
- Convenient Coma: At the end of Volume 16 due to Rizevim stealing her Longinus. She wakes up at the end of Volume 19 after a fragment of the Grail was given to her.
- Damsel in Distress: Marius takes her hostage in order to abuse the power of the Sephiroth Graal.
- Dhampyr: A half-breed due to her mother being a human.
- Hes All Grown Up: Has this reaction towards Gaspar. It brings her joy, but simultaneously saddens her that she wasn't able to see it.
- I See Dead People: The Holy Grail forces her into contact with the souls of the dead, slowly eroding her sanity. Living people talking with her are often confused when she randomly starts speaking an incoherent language to souls they can't see. She stops suffering from this after waking up from her coma.
- The Medic: For Rias team in the Azazel Cup, since Asia is serving Issei.
- Satellite Character: She's largely defined as Gasper's childhood friend and has little interaction with anyone else. Even when she joins Rias' team in the Azazel Cup, her role is quite minimal.
- Superpower Lottery: Her Longinus, Sephiroth Graal (Also known as Holy Grail of the Secluded World):
- Came Back Strong: It can get rid of weaknesses of beings it brought back to life.
- Fountain of Youth: When combined with the powers of Forbidden Balor View and Senjutsu it can create a potion to restore someone's body to its prime
- Healing Hands: Can heal the same as Twilight Healing but it is less effective.
- Healing Factor: Can give other people this.
- Suspiciously Similar Substitute: To Asia; a blonde girl possessing a Sacred Gear with healing properties who was initially ostracized by everyone around her except a male member of Rias' peerage. Both suffered the lethal extraction of a Sacred Gear (Asia genuinely dying and resurrecting as a Devil thanks to Rias, while Valerie happened to have more than one Holy Grail within her to keep her alive). After trading Asia into Issei's peerage, Rias makes Valerie her Bishop for the Azazel Cup.
Marius Tepes is a pure-blood vampire who is the fifth in-line to become the next head of the Tepes Vampire Faction. He forms an alliance with the Khaos Brigade in order to initiate a coup d'etat to take the vampire faction for himself.
- Arc Villain: The main antagonist of Volume 16.
- Character Death: Gasper kills him with his newly awakened Balor abilities due to Marius' treatment of Valerie.
- Dirty Coward: In his final moments, when he realizes that the Holy Grail cannot protect him from Gasper's power, he pleads for his life.
- Eaten Alive: He gets eaten alive at the hands of Gasper Vladi.
- Exact Words: At Gasper's request, he promises to "release" Valerie from her duties with the Holy Grail. The rest of the club quickly catches on that he's going to release her from the Holy Grail itself, and Sacred Gear possessors die when their Sacred Gear is extracted.
- Fatal Flaw: His sadism and over-confidence is what eventually does him in.
- Faux Affably Evil: He may come off as a polite and generous, but he is a Manipulative Bastard who is working for the Khaos Brigade.
- Healing Factor: After extracting Valerie's Holy Grail, he casually lets Rias vaporize his upper half to show the potency of the Holy Grail's rejuvenation powers. However, Gasper Balor's power exceeds even that, and he soon realizes, to his horror, that his lost limbs are staying lost.
- Smug Snake: Thinks that just because he's a pure-blood vampire, he's always the smartest in the room, and can do whatever he wants. He learned too late how wrong he is.
- Spare to the Throne: He's fifth in-line to become the head of Tepes.
- Swallowed Whole: How he met his end at the hands of Gasper Vladi.
- Unhand Them, Villain!: He does this to Valerie. He promises Gasper that he'll "release her from service" after she's fully established his rule over the Tepes faction using her Holy grail powers, and he does, by using the same ritual that Raynere used on Asia to steal her sacred gear, and "release her from life" and laughed at Gasper for it while the latter was Forced to Watch, ignoring Gasper's pleas to spare her... Boy was that ever a mistake.
- Villainous Breakdown: He completely loses it when Gasper goes balance breaker in front of him, and tears his faction apart, effortlessly.
- Villains Want Mercy: Once he's overpowered by Gasper, he tries begging his life, but it doesn't work.
- Ascended Extra: After appearing a minor character during volumes 14 and 16, she becomes a more prominent character from Volume 21 onwards.
- "Ass" in Ambassador: When she's dispatched to recruit Gasper towards the end of the vampire civil war, Elmenhilde tries to have the Occult Research Club hand over Gasper by force or risk having their diplomatic relationships go south, to the point that she even taunts Gasper and Issei out of prejudice. Predictably, Issei and Rias do not react well to it. However, she's a good guy by the end of the day, which is further cemented by her reconciliation with Issei.
- The Atoner: By volume 21, she felt the need to become Issei's lover to make up for her earlier actions when they first met.
- Babies Ever After: By the time of EX, she has a daughter with Issei, named Ernestine.
- Break the Haughty: Played straight, and for laughs. The open conflict between the Carmilla and Tepes factions brought about by Rizevim and his conspirators really does a number on her, but she's still haughty at the end of it, and then Sona's peerage gets a hold of her, and Hilarity Ensues.
- The Bus Came Back: She was Put on a Bus after volume 16 and was absent until volume 21, where it's revealed that, when Issei helped her on the Gundam Gunplas mission, she is more of a selfless girl who falls in love with Issei.
- Character Development: She starts off as a self-centered glory hound vampire who has a low opinion of those who aren't pure-blooded vampires; Issei understandably does not take this well. Around the time of Rizevim's death, Issei helps Elmenhilde and Seekvaria free a village from the control of a vampire and a devil using Gundam Gunplas. Thanks to those, she becomes a selfless girl who becomes Issei's lover and a member of his team for the Azazel Cup.
- Cute Clumsy Girl: Just like Asia, Elmenhilde has a habit of tripping over herself.
- Et Tu, Brute?: Her reaction to her male kin, including her uncle and cousin, betraying her in the civil war is utter shock.
- Everyone Has Standards: Even though she has an initially low opinion of those below her, such as Issei and Gasper, she's completely horrified by Rizevim's assault on the Carmilla and Tepes factions.
- Fantastic Racism: Like the rest of her kind, Elmenhilde originally has a low opinion of anyone who's not a pure-blooded vampire. All of her racism is dropped after she rebuilds her homeland and Issei teams up with her to free a village involving the Gundam Gunplas.
- Humble Pie: She becomes deeply affected by her homeland's destruction so much so that she has to rebuild the Carmilla and Tepes territory. She becomes even less of a jerkass by the time of Volume 21.
- Hypocrite: During the final days of the vampire civil war, she tries to have Gasper join her Carmilla faction to fight the Tepes faction to exact revenge on those who have discriminated against him for being half-human... all the while dismissing other half-bloods like his childhood friend Valerie.
- I Hate Past Me: Once the Vampire Civil War is over, Elmenhilde takes a dim view of her actions and reconciles with Issei in an effort to atone for her misdeeds.
- Jerk with a Heart of Gold: She refused to have the Occult Research Club get involved in a vampire civil war out of prejudice and underestimated Issei's powers. When Issei and Elmenhilde reach an understanding after the Gundam Gunplas mission, however, she's willing to put all differences aside to fall in love with him, and join his team for the Azazel Cup.
- Kick the Dog: She taunts Issei for being a devil to irritate him during their first meeting.
- Misery Builds Character: She becomes a much better person after her life takes a massive turn for the worse thanks to Rizevim.
- Proud Warrior Race Guy: Being a pure-blooded vampire, she doesn't like devils or anyone down below her very much. This changes thanks to her rebuilding the Carmilla and Tepes territories and Issei helping her free a village involving the Gundam Gunplas.
- Took a Level in Kindness: After rebuilding the Carmilla and Tepes territories in the aftermath of the civil war, along with Issei helping her with the Gundam Gunplas mission, she begins to lose her arrogance, becomes open to everyone and falls in love with Issei.
- Tsundere: Her introduction in volume 21 amusingly reveals she is this for Issei. Upon mention of his name, she immediately expresses High-Pressure Emotion and goes into Suspiciously Specific Denial. Azazel, in particular, loves to taunt her about this.
- Underestimating Badassery: She initially underestimates Issei's power and reputation when they first meet. Understandably, Issei does not react well to it.
- Weak, but Skilled: During the Azazel Cup, its noted that her own abilities are actually nothing special compared to other high-class vampires, but she can make use of her comrades abilities by consuming their blood.
- Voiced by: Yoshitsugu Matsuoka (Japanese), Ben Phillips (English)
Freed Sellzen is a psychotic exorcist working for the fallen angels and a recurring antagonist of the series.
- Artificial Human: Made from different patterns of genetics of those who carried the blood of the original Siegfried to use Gram.
- Ax-Crazy: He's both insane and aggressive, attacking whoever gets on his nerves, or simply catches his fancy when he's "in the mood."
- Back for the Dead: After having been cut down in Volume 3, Freed would meet his ultimate end in Volume 6 at the hands of Kiba.
- Blood Knight: Freed may be an exorcist, but he doesn't give a flying crap about God. The only reason he's an exorcist is so he can kill demons and slake his bloodthirst.
- Body Horror: His body takes on the terrifying form of a chimera during his final appearance.
- The Dragon: He plays this role to Raynare in Volume 1, then to Kokabiel in Volume 3, and again to Diodora in Volume 6, although it's up for debate as to whether he was really serving the latter or just looking for revenge against the Research Club.
- Evil Is Hammy: He seems to overact his scenes, and seems to enjoy doing it.
- Fatal Flaw: His insane behavior leads to him getting killed by Kiba.
- Gratuitous English: He peppers his speech with random English words.
- Half the Man He Used to Be: How Kiba ultimately kills him.
- Hiding Behind Religion: He never believed in God in the first place; Freed only joined the Church and became an exorcist so he could kill and satisfy his bloodlust without consequence.
- I'm a Humanitarian: In the sixth volume, he gets turned into a chimera and when the club meets with him again, he's shown to be eating the two remaining knights Diodora had.
- Killed Off for Real: After being revived as a chimera, Freed dies permanently in Volume 6 when Kiba slices him apart nearly instantly.
- Knight Templar: Averted. His wanton slaughter of supernatural being has nothing to do with any higher purpose. Freed never even believed in God, and only became an exorcist so he could slaughter things with impunity.
- Large Ham: We think his seiyuu had a hammy time delivering his lines.
- Laughably Evil: As warped as Freed is, he's a joy to watch between his mood swings and bizarre mannerisms.
- Light Is Not Good: Freed is an exorcist of the Church, who wields holy weapons against the creatures of the underworld. He is also an Ax-Crazy maniac.
- Long-Lost Relative: Made by the Sigurd Institution the same as Siegfried and Lint, so he is artificially related to them. Especially to Lint as he and her are made from the same genetics.
- The Mad Hatter: In the English dub, he gleefully refers to himself as a "psycho priest free agent."
- Maniac Tongue: In almost every other scene.
- Minor Injury Overreaction: He gets punched in the face by Issei and from there proceeds to lose all sanity.
- Opt Out: After Raynare is defeated by Issei, Freed hightails it outta here. In the anime, he did promise to help if he got sex, but bailed when she refused to deliver.
- Perpetual Smiler: Pretty much always has a twisted grin plastered on his face.
- Recurring Boss: He attacks the Occult Research Club multiple times over the course of the story: In the first volume, when Issei visits a client who Freed had just killed, and again outside the abandoned church where he fights them to protect Raynare; In the third volume, when he battles Kiba and Xenovia for Kokabiel wielding the Excaliburs; and finally in the sixth volume, during the Rating Game against Diodora, having devoured two of Diodora's knights and become a chimera. Here, he is killed by Kiba.
- Red Eyes, Take Warning: He has red eyes and is a villain.
- Run or Die: After Raynare is defeated, Freed is forced to abandon the fight.
- Screw This, I'm Outta Here!: He heads for the hill when Issei defeats Raynare and Rias is about to kill her.
- Sex Is Violence: He outright states that he's getting hard just from the "killing intent" in Akeno's gaze, and generally acts as if torture and murder are his favorite turn-ons.
- Shout-Out: The Excalibur itself is a shout out to a lot of series so it isn't that new; it's how he says it becomes this trope.
- The Only One Allowed to Defeat You: Towards Issei for hitting his face.
- Teen Genius: Was apparently an exorcist when he was 13 years old.
- Villain Decay: At the start he is presented as a serious threat and actually proved to be a challenge even for Kiba and Koneko. Five volumes later, he gets one-shotted by Kiba.
- Wake-Up Call Boss: Played with. Issei hasn't really fought any battles yet (and the ones he was involved in usually ended up getting him killed, or at least hurt badly). But when he encounters Freed for the first time, he knows that he's outclassed and even Rias apologizes to him since they hadn't realized a rogue exorcist was around.
- See her entry on the Occult Research Club page.
- See her entry on the Occult Research Club page.
Touji ShidoTouji Shido is the father of Irina Shido who is currently a pastor, formerly an exorcist.
- Cloudcuckoolander: Is where Irina gets it from.
- Doting Parent: One for Irina.
- I Want Grandkids: Gives up on this when Irina becomes an angel, he regains hope when Micheal has him deliver the doorknob, that leads to the baby making room to Issei and Irina.
- Shipper on Deck: Ships Issei and Irina, he happily encourages them to use the baby making room alot. Implies he ships since they were children.
Masaomi YaegakiMasaomi Yaegaki is a former exorcist of the church who fell in love with a devil who used to manage Kuoh town before Rias. He is resurrected by Rizevim in Volume 18, and goes on the hunt for the people responsible for ruining his life. Particularly, Irina's father, Touji Shidou.
- Back from the Dead: He was resurrected back from the dead by Rizevim thanks to the Sephiroth Longinus.
- Blood from the Mouth: He suffers this when Rizevim kills him.
- Cool Sword: A sword fused with half of the Venom Blood Dragon, Ama no Murakumo.
- Dropped a Bridge on Him: Masaomi is unceremoniously killed off by Rizevim as he reconciles with Issei.
- FaceHeel Turn: After his loved one was killed, he decided to seek revenge on the church by becoming a member of the Khaos Brigade.
- Fallen Hero: He was a former exorcist who was revived by Rizevim to seek revenge on the house of Bael and the church for the sake of his former lover.
- Famous Last Words: "Ah, I would want - in this day and age... to meet you again..."
- Go Out with a Smile: He smiles at Asia just before he dies.
- Hydra Problem: Thanks to the fusion, the sword has multiple dragon heads that breathe fire and poison.
- It's Personal: He gets resurrected to avenge his lover's death at the hands of the church and Bael.
- Playing with Fire: Each of the heads can breath out fire.
- Poisoned Weapons: And the fire itself is considered poisonous if it burns the opponent.
- Redemption Equals Death: After being freed of the Dragon's influence thanks to Issei and Xenovia, Rizevim kills him just as Masaomi reconciles with Issei.
- Revenge: He wants to exact revenge on the house of Bael, as well as the church, for separating him and his loved one. Even going so far as to joining Qlippoth's battle against Heaven just for the sake of killing Touji.
- Rule of Two: He was once Touji Shidou's subordinate at the church.
- The Scapegoat: Volume 20 reveals that his ill-fated romance, and the aftermath, was used as a cover to hide the corruption within the Rating Games, specifically, the existence of the King piece, and its abuse.
- Shoot the Dog: Strangely enough, it's also Rizevim that sends his soul back to the afterlife after he was finally coming to terms with Issei.
- Star-Crossed Lovers: He's an exorcist while she's a devil. And this was at the time when the three sides were still at war with each other. There was no way it was gonna end well.
Cardinal Priest Vasco Strada
Vasco Strada is the 3rd top-ranking exorcist member of the Vatican Church with the rank of Eminence Cardinal Priest. Vasco was the former wielder of Durandal before it was passed down to the next generation. Due to the exorcists losing their role-in-life on account of the Devils and Vampires aiming for peace, he initiates a rebellion in Volume 19.
- Absurd Cutting Power: Using a replica of Durandal he cuts Rias' Extinguished Star apart.
- Authority Equals Asskicking: Being a Eminence Cardinal Priest when he was a member of the Vatican, he's quite capable of wiping the floor with others.
- Badass Grandpa: The guy is 87 years old, and was still proving to be a badass.
- Big Damn Heroes: He comes to the rescue during the battle with Trihexa in volume 21.
- BFS: Fought in the exorcist rebellion with a replica of Durandal.
- Cool Old Guy: He clearly enjoyed his battle against the members of team DxD to the point that he was basically a Stealth Mentor for the young guns that fought against him. Even after his defeat, and heading to Hell for interrogation, he provided Kiba and Gasper parting gifts; a survivor from the Holy Sword experiment, and a fragment of the Holy Grail.
- A Father to His Men: It's implied that the reason he issued a challenge against team DxD is so that he can give the exorcists a means of closure after the peace treaty made their jobs irrelevant. Fortunately, Dulio sped the process up without the rebellion ending in tragedy]].
- Graceful Loser: He takes his defeat and later interrogation with dignity.
- He's Back: Decides to return to action by helping the fight against Trihexa and the Evil Dragons. With the announcement of the Azazel Cup, he joins Rias' team to replace Xenovia (who is transferred to Issei's). He even gets his prime body back thanks to the combined power of the Sephiroth Graal, Forbidden Balor View and Senjutsu.
- Large and in Charge: He's the leader of the exorcists and a high-ranking official of the Vatican Church, and he stands at 2 meters (6'6") tall.
- The Leader: He serves as the rebel exorcists' leader.
- Luxury Prison Suite: After being interrogated for leading the Exorcist rebellion, he gets to live a quiet life working on a normal farm within a prison barrier.
- Master Swordsman: He's quite capable of wielding a sword.
- Nice Guy: He is a very compassionate man who doesn't resent Devils or Fallen Angels.
- Retired Badass: Was the previous wielder of Durandal, and is able to prove in the current time that he can fight with a weaker Durandal replica against the Occult Research Club/Saji team. The only one that proved to be too much for him in swordsmanship due to his age was Arthur after a brief interruption.
- Rule of Two: The master to his apprentice, Teodoro.
- Shipper on Deck: Wants to give his blessing as a priest at Issei and his harem's wedding ceremonies.
Cardinal Deacon Ewald Cristaldi
Ewald Cristaldi is the 4th top-ranking exorcist member of the Vatican Church with the rank of Eminence Cardinal Deacon. Ewald was the former wielder of Excalibur before the sword was split into fragments. He stood alongside Vasco during the exorcist rebellion.
- Authority Equals Asskicking: As a Cardinal Deacon of the Vatican, he can use his swords to attack his enemies.
- Cool Sword: Fought in the exorcist rebellion with a replica of Excalibur.
- The Lancer: He is Vasco's second-in-command during the exorcist rebellion.
- Retired Badass: Was the previous wielder of Excalibur, and is able to prove in the current time that he can fight with a weaker Excalibur replica against the Heaven/StudentCouncil/Kiba team.
- The Stoic: No matter the situation that he is in, Ewald is a very calm and collected person.
- Warm-Up Boss: He is the first to be defeated primarily to show off the strength of Dulio's "Speranza Bolla di Sapone" technique that caused all the rebel exorcists Mooks to be forced out of commission.
Eminence Cardinal Bishop Teodoro Legrenzi
Teodoro Legrenzi is the 2nd top-ranking exorcist member of the Vatican Church with the rank of Eminence Cardinal Bishop. Despite his young age, Teodoro was given a high Church rank due to being one of the Miracle Children, and like Vasco and Ewald, he participated in the exorcist rebellion.
- Authority Equals Asskicking: Being one of the top-ranking exorcists in the Vatican, he is quite capable of fighting enemies.
- Big Damn Heroes: He steps in to block Xenovia's attack when Vasco was at his limit against team DxD.
- Dark and Troubled Past: Devils had murdered his mother and father, and Teodoro vowed to exact revenge.
- Freudian Excuse: He has a good reason to hate Devils since they murdered his parents long ago.
- Half-Human Hybrid: He's half-human and half-Angel.
- It's Personal: He wants to avenge the Devils for murdering his parents.
- My God, What Have I Done?: He felt horrible about what he did after being defeated by team DxD.
- Nervous Wreck: It doesn't take much to send the poor boy into hysterics.
- Our Angels Are Different: Teodoro is one of the Miracle Children; meaning that he is one of the few humans that was blessed with the ability to become an angel.
- Out of Focus: Compared to Vasco and Ewald, his role during the Exorcist rebellion in Volume 19 is surprisingly very minor.
- Revenge: He is hostile to team DxD due to his desire to avenge the death of his parents.
- Rule of Two: The apprentice to his master, Vasco.
- Student and Master Team: He forms one with Vasco as his master.
- This Is Unforgivable!: His viewpoint of Devils after they killed his parents is that he would never forgive them for their actions, and outright says that to the Occult Research Club in Volume 19. He gets better after realizing what devils are truly capable of thanks to Yuto, Xenovia and Irina.
- Young and in Charge: Teodoro's the second highest rank in the Vatican. The Pope being the only one he stands behind.
- Gorou Hyoudou voiced by: Mitsuro Ogata (Japanese), Sonny Strait (English)Miki Hyoudou voiced by: Sachiko Kojima (Japanese), Jessica Cavanagh (English)
- Age Lift: They're drawn noticeably younger in the Manga compared to the anime.
- Doting Parents: Surprisingly, to Asia which Issei notes but doesn't seem to care. Volume 20 also revealed they did this to Issei when he was little.
- Dark and Troubled Past: Volume 20 reveals Issei was their third attempt at a child after having two miscarriages over the course of almost a decade.
- Determinator: What else can you call a couple who suffered two miscarriages within almost ten years and instead of giving up or adopting, though they do it unofficially for Asia, took what they learn and did the best they could to have a child.
- Did You Just Punch Out Cthulhu?: Miki slaps Belial for forcing Issei to drink the dragon blood, reverting Issei to his original dragon form.
- Grandma, What Massive Hotness You Have!: If it wasn't for her smile lines you could swear she was ten years younger.
- Ill Girl: While not completely frail, Miki had a poor constitution for carrying children to term resulting in two miscarriages until Issei was conceived.
- I Want Grandkids: They were initially on the verge of giving up due to Issei's perverted nature, but later on as Issei (unknowingly) builds his harem, they started to regain hope. They are probably overjoyed in the future, thanks to Issei having at least twenty children from his harem. That's right, people, twenty kids.....
- Laser-Guided Amnesia: After Rias takes Issei back to his house in Volume 1, she erases the memories of his mother catching them in the bed naked.
- Like a Daughter to Me: Treats all the girls living with them like their are own daughters especially Asia.
- Locked Out of the Loop: While they know that Issei's harem is staying at his house, what they don't know is that their house is occupied by the sister of one of the four lords of hell, a half-fallen angel-half human-turned-devil, a nun-turned-devil, a Cat Girl, a former exorcist-turned-devil, a reincarnated angel, a valkyrie-turned-devil and the most powerful dragon. Not to mention, they don't know that their son is also a dragon-devil. Well, until volume 20, at least...
- No Name Given: Issei's parents went unnamed, even when spoken to they were called mother and father by all the residents of the household until Volume 25 which finally gave Issei's father his given name: Gorou and Shin Volume 2 which gave Issei's mother her given name: Miki.
- Not So Different: It was hinted that both his parents were lustful back in their days where Gorou get ecchi stuff and Miki wore a Naked Apron. There's also the fact Miki has no problem with the girls doing so as well. Gorou also makes an off-hand comment suggesting being a Harem Seeker in his youth when he stumbles upon Rias and Asia in Naked Apron.
- Only One Name: Issei's father was referred to as Mr. Hyoudou until his first name was revealed in volume 25.
- Open-Minded Parent: They take the whole devil humanoid dragon business in stride.
- Parental Substitute: She becomes a mother figure to all of the girls living with them, even those who have no real mother.
- Shipper on Deck: Ships Issei and any girl who is interested in him.
- So Proud of You: While they're best hope for Issei was to be hard working person with a family, they are positively tickled pink when they find out he's a celebrity in the underworld and pretty damn rich due to the royalties from Oppai Dragon.
The Hyoudou-Gremory siblings are Issei's children with his haremettes. They come from the future to capture Loki and analyze his powers in order to lift a curse he has placed on Asia in the future.
General tropes pertaining the siblings (note that the tropes below are specific to each child only. Check the Occult Research Club page for the tropes shared with their parents):
- Adorkable: Despite being God-Class and outranking their parents from the past, they are still teenagers and show some awkward cuteness like their parents had, mainly Ex when talking about breasts, Zen for being a little emotional when talking about Asia, or Airi when she believed that she was ready to learn her mother's secret recipe for her meal.
- Aerith and Bob: Kurenai, Robertina, Ernestine, Airi versus Ex, Zen, Shin, and Helmwige. Even more strange considering that some of them are gender-neutral names (Kurenai and Shin can be used for both males and females), some others are not popular, but otherwise legitimate names, and one is completely out of the blue (Ex). Justified, when you realise that each child's name has its own meaning to their particular mothers.
- Badass Family: All the children can hold their own in a fight, especially the older ones. This comes to a head when they fight together with their parents in the last two chapters.
- Beware the Nice Ones: Usually they show off some class and friendly demeanor, especially Airi, Shin and Kurenai, but you will have to remember that they are the children of Issei.
- Bishōnen: The boys all look more like their mothers than like Issei. (Fortunately for them, in Azazel's opinion.)
- Child Soldier: They are forced to enter the battlefield at very young age thanks to a war happening in the future. The youngest sent into the present timeline was twelve.
- Half-Human Hybrid: All of them have unique bloodline combinations from their parents.
- Lightning Bruiser: In particular with the elder, advanced siblings, in that they can use Kiba's signature God-speed with ease, if not faster, and they can stop a large-scale bombardment without breaking a sweat, even going as far as stopping the projectiles ala The Matrix. Ex and Airi are especially noted by Azazel to even surpass their mentor in speed.
- Signature Move: While each of the children has his/her own specialized techniques, all of them are able to use their father's trademark Boost with their dragon power.
- Sibling Team: Naturally.
- Strong Family Resemblance: Nearly all of them resemble a gender-reversed version of their mothers, but mainly Airi, who looks exactly like Asia, but with a more twisted personality which she inherited from Issei.
- Superpowerful Genetics / Hybrid Power: As a rule of thumb, each kid uses their mother's signature fighting style, with Issei's dragon power inherent in their bodies to give them support to execute powerful techniques (with the exception of Ex and Airi, who both wields Longinuses and have their own unique combat styles). They are also quasi-immortal (or at least have much longer lifespan), thanks to the Great Red's genes they inherited from Issei.
- Superior Successor: All of the older ones are on a level far beyond their parents were at at the same age during the time period they traveled back to (sometime after Volume 14). Lampshaded by Azazel, who noted that the older siblings are basically Ultimate-Tier or even God-Tier, with Ex in normal condition being capable of killing off vanilla Loki without breaking a sweat.
- Teen Genius: They are barely teenagers, yet their mastery of their abilities easily surpasses their parents at present (who are hinted to be their post-volume 18 selves).
- Worf Had the Flu: When they finally confront Loki and Metal Fenrir, they cannot even put a dent in the direwolf and are blasted by the god's magic. Justified, since the new EX version of Fenrir is a perfected type with superior cyborg body, which later acts as Loki's version of the Scale Mail armor, amplifying his power.
Ex Gremory is the sixteen-year-old son of Issei and Rias Gremory. He is tied with his older sister Airi as the strongest of the siblings and, like her, serves as a vanguard in the future war.
- The Ace: Ex is one of the main vanguards in the future Evil God war, and boy is he good at what he does.
- Achilles' Heel: His primary weakness is that he cannot use his Boosted Gear Diabolos' Powered Armor consecutively due to its unstable nature, which proves vital when he needs the firepower to even out Loki with Fenrir-based, Scale Mail equipped after activating it against an Elite Mook.
- Broken Ace: Played for Drama. His main problem comes from his one-sided Daddy Issues with Issei (which, compared to what Issei went through in the main series, is comparatively minor, and Ex never outright states it in front of his dad), but later amends it by himself in the end since when he realizes that yes, the dad that he despised so much would go far to help his family.
- Cool Sword: His personal sword, Galatine III, which can be fused with his Boosted Gear (it's an alchemy-metallurgical synthesis version of the original Galatine, the companion blade to Excalibur wielded by Sir Gawain, Arthur's nephew). Ex chooses it by himself since he explicitly does not want a version of Ascalon, his father's sword, and Kurenai adds that it's Galatine's unchippable nature that makes it a fitting combo to use with Power of Destruction.
- Covert Pervert: Like his Dad he has a love of Breast, he's just more secretive about them.
- Double Meaning: His name. The official explanation is that "Ex" is taken from his mother's Finishing Move, Extinguish Star (in Japanese, the first syllable of the technique's name is spelled イクス, "Ikusu," and his name has sometimes been romanized as "Ix"). Another interpretation is that his name (in katakana) is an acronym of Issei and Sirzechs' name (I for Issei, kusu for Sirzechs [Saazekusu]), similar to Boruto, who is also named along similar lines after his uncle Neji. However, this becomes a bit lost in the romanization.
- Expy: Ichiei Ishibumi based Ex on Boruto.
- Generation Xerox: His traits are mostly descended from Rias, but he also shares Issei's fondness of breasts and interest in erotic things (albeit subtly).
- I Hate You, Vampire Dad: Has shades of this because Issei cannot save Asia and be there when they need him, but eventually averted when the old man himself appears to protect his children from the UL threat.
- Master Swordsman: One of Kiba's top students along with Zen and Shin.
- Powered Armor: Just like his father, except that Ex's version very much takes cues from Issei's Diabolos Dragon form.
- Red Baron: God Slayer of the Scarlet Blade (his nickname within The Alliance). Alternatively, Crimson-haired Sekiryuutei or Sekiryuutei's Crown Prince.
- Spell My Name with an "S": Invoked by Western fans who were trying to figure out the English version of his name before all of the EX chapters had been released. His name as spelled in katakana is properly pronounced "Ikuzu"; this has alternately been romanized as "Ixis," "Ix," and "Ex," with "Ex" eventually becoming the most common variation because he's named after Rias' "Extinguish Star" technique. This has had the unfortunate side effect of leading many non-Japanese-speaking fans to decide that he is the main character simply because the spinoff is called High School DxD Volume EX. (He really isn't. The "EX" in the title simply designates that the story is a spinoff, and it should be read as E-X, not "ex.")
- Superpower Lottery: He won the biggest among his siblings since he can wield both his mother's Power of Destruction and his father's dragon powers (with a version of Boosted Gear to boot).
- Training from Hell: He gets this mostly from Vali. His training routine involves how to use and control his dragon powers, the proper use of the Boosted Gear and combining it with his sword and Power of Destruction, and washing the dishes every day for the first six months.
Airi Hyoudou is the eighteen-year-old daughter of Issei and Asia Argento, Airi is the eldest daughter of the siblings. Along with Ex, Airi is one of the main frontline powerhouses of the Alliance in the future war.
- Action Girl: contrasting with her mother.
- Bare-Fisted Monk: Her primary fighting style. It is heavily hinted that her mentor is none other than her uncle-in-law, Sairaorg Bael, whom she respects very much.
- Bully Hunter: Does not really like it when Loki "bullies" her mother by putting an irreversible curse.
- Cool Big Sis: Is considered this by all the younger siblings.
- The Dreaded: Played for Laughs. The younger siblings fear her because they cower when she unleashes her angry expression.
- Expy: She is an older sibling version of Sarada.
- Fun with Acronyms / Double Meaning: While Airi is a legitimate Japanese name (her name in kanji is written 愛理, meaning ''strong love''), she states that her name is also an acronym to her parents' name (A for her mom Asia, I for her dad Issei, and Ri for her mother-in-law Rias).
- Made of Iron: She survives being clawed in the gut by an enhanced version of Fenrir. Granted, her armor mostly dampens the damage, but even with that level of protection, most characters (including Gods!) in the main series will bleed to death. After receiving some treatment from Asia, Airi brushes the damage off like nothing and pays back by hitting Fenrir's nose with a straight punch.
- Number Two: She is the second-eldest of the siblings and second-in-command (after Kurenai) and is tied in strength with her younger brother Ex.
- Plucky Girl: A combined trait between her parents. Her reaction when she was able to score a kill on a God-Class UL with a full-on punch?
- Airi (while cleaning up the mess after the battle): I overkilled it *sticks her tongue out*.Other siblings: Yeah, right.
- Powered Armor: By the virtue of her Artificial Longinus, Gigantis Maiden Robe, which uses Fafnir as the power source. Asia passes the Dragon King to her.
- Strong Family Resemblance: Airi greatly resembles her mother Asia Argento, just with a more twisted personality which she inherited from Issei.
- Yamato Nadeshiko: A rare non-Japanese example (especially since her father is not considered "Japanese" anymore by being fully draconic), which is very much like her mother.
Kurenai Himejima is the son of Issei and Akeno Himejima, Kurenai is the eldest of the siblings. He is a Grigori researcher.
- Badass Bookworm: Like Azazel before him, he is very good at kicking ass and a genius inventor, with his byproducts including Ex and Airi's Artificial Longinuses and the synthesis swords.
- Big Brother Instinct: Whenever his younger siblings need help, he will come to them.
- Expy: A genius, long-range fighter version of A, the Fourth Raikage.
- Facepalm: When he and Zen watch their younger parents' recorded antics.
- Family Theme Naming: His name continues the Himejima family tradition of naming their descendants after the color red and its variation (''Kurenai'' means "crimson").
- Interestingly enough this is actually subverted when the name is spelled in kanji. Other members of the Himejima family, even Akeno, use "朱" for red while Kurenai uses "紅".
- Light 'em Up / Shock and Awe: He inherits Holy Lightning from his mother and grandfather and develops it to the point of creating his own version of Holy Lightning armor.
- Summon Magic: As a Himejima family trait, he can summon a Sacred Beast, but it's more in the lines of the Chinese phoenix, Fenghuang, rather than Suzaku / the Vermillion Bird, since he is not in the primary bloodline.
- Squishy Wizard: Averted. Kurenai mostly fights from a distance, but his defense and speed are also top-notch.
Zen Quarta is Issei's seventeen-year-old son with Xenovia Quarta. The team's communications hub, he wields a synthesis version of his mother's sword, Durandal IV.
- BFS / Implausible Fencing Powers: Like his mother, but Zen can handle his sword in a much lighter fashion, allowing for fast, precision cuts.
- Facepalm: When he and Kurenai watch their younger parents' recorded antics.
- Genius Bruiser: With the implication that his mother is an Education Mama, Zen is very well-versed with their enemies and the situation he is in (although still not reaching Kurenai's intelligence levels), while at the same time is a tough-as-nails swordsman.
- Master Swordsman: One of Kiba's top students along with his brothers Ex and Shin.
- Mix-and-Match Weapon / More Dakka: His sword is a gunblade, and the gun aspect is a machine gun which uses power-boosted .50 BMG bullets.
- Mr. Exposition: He takes this role to explain things for Azazel.
- Punny Name: His name is a shortened version of his mother's name (originally read as "Zenovia" both in Japanese and English), and Zen itself means "absorption" or "meditation" as in the Zen school. The boy himself is very calm and calculating, as opposed to his mother's brash attitude in her youth.
- This becomes Lost in Translation since his mom's name is officially romanized as Xenovia.
- Zen Survivor: He displays this attitude to go with his Punny Name above.
Shin Shidou is Issei's seventeen-year-old son with Irina Shido.
- Dual Wielding: He wields two katanas.
- Half-Human Hybrid: While most of the siblings are this, Shin is a unique case where he is a Human-Angel-Devil-Dragon hybrid.
- Genki Guy: A trademark trait inherited from his mother.
- Holy Hand Grenade / Light 'em Up: His powers, which is common for angels and inherited from Irina.
- Katanas Are Just Better: Seems to be a preference he inherited from his mom (Irina previously wields Excalibur Mimic in the form of a katana for simplicity).
- Master Swordsman: One of Kiba's top students along with his brothers Ex and Zen.
- Meaningful Name: Shin means "heart". He is half-angel and very kind.
- Shout-Out: His katanas are Kashuu Kiyoumitsu and Yamato-no-Kami Yatsusada.
- Fridge Brilliance when you know that the swords historically belonged to Okita Souji, Kiba's swordmaster. It is possible that Okita gave it to Shin via Kiba.
- Spell Book: How he uses his holy spells and stores his two swords.
Shirayuki and Kurobara
Shirayuki and Kurobara are the youngest siblings and Issei's Nekomata daughters with Koneko Tojo and Kuroka, respectively. They are twelve-years-old.
- Big Eater: A trait they inherited from their mothers.
- Cat Girl: Like their mothers, they resemble cats.
- Half-Identical Twins / Alleged Lookalikes: Inverted and Zig-zagged. Azazel notes that the Nekomata sisters are similar to each other, but they have enough distinct features inherited from their mothers to differentiate between the two. It doesn't help that they are born at the same time in the same day (suggesting that Issei had a threesome with their moms). Way to go, Harem King!
- Shout-Out Theme Naming: The sisters are named after fairytale characters. Shirayuki is Snow White, while Kurobara means "Blackthorn", which is a native Britannic tree, commonly known as the nickname of Sleeping Beauty.
Robertina Hyoudou is Issei's sixteen-year-old daughter with Ravel Phenex. She's Gasper's assistant in their mission in the story, along with Helmwige.
- Animal Motifs: Phoenix, just like her mom.
- Daddy's Girl: She respects her father the most out of all her siblings.
- Deadpan Snarker: She is more prone to snark, especially to Ex.
- Genius Bruiser: She can kick ass moreso than her mother, and has Sherlock Scan skills, which is essential in their mission to obtain the cure for Asia's curse from Loki.
- Lineage Comes from the Father / Shed the Family Name: A variation. Robertina cannot bear the Phenex surname since Ravel left her clan and gave herself to marry Issei, so she goes with her father's family name.
- Meaningful Name: Robertina means "bright fame" (a feminine version of Robert), referring to her mom's Ojou origin.
- Mega Twintails: Not just two, but four.
- Ojou: Like her mother, but Robertina is more relaxed.
Helmwige is Issei's seventeen-year-old daughter with Rossweisse. Also Gasper's assistant in the mission.
- Barrier Maiden: She is taught in her mom's (rather expensive) sealing technique.
- Braids of Action: She ties her silver hair into a single long braid.
- Deadpan Snarker: Comments that her mother will faint when she knows her seal technique fails, because of the expensive development budget Rose had thrown in.
- Facepalm: Does this while saying above comment.
- Sherlock Scan: Along with Robertina, Helmwige can obtain information by scanning any item that she deems important.
- Valkyries: a Dragon Valkyrie to be exact, because she also inherits her dad's dragon powers, and her armor is based on Issei's Scale Mail.
Ernestine Karnstein is Issei's daughter with Elmenhilde Karnstein.
- The Apprentice: Gasper's number one pupil.
- Dhampyr: The first female draconic example.
- Summon Bigger Fish: She brought along her father in dragon form to help her siblings finish their job.
- Suspiciously Similar Substitute: A variation. Since Issei's children who come from the future, in essence, replicate Rias' peerage in terms of the members (with slight differences), Ernestine is considered to be this trope to Gasper since she is basically his female version without his Sacred Gear.
- Unexpected Character: She brought her father to finish her siblings' job at the end of EX.
Mordred Hyoudou is Issei's son with Le Fay Pendragon. He is only mentioned in the spin-off and does not appear in person due to the circumstance of the story. The Harem King Memorial artbook reveals his name to be Mordred Hyoudou, which is pretty much a natural choice.
- Magic Knight: Subverted. Robertina hints that he can wield his uncle's sword, Collbrande, with ease, but chooses to stick to being a wizard like his mom. Considering who his namesake is, this is no coincidence, if a bit jarring.
- Nom de Mom: Averted, like Robertina, Mordred has Issei's surname instead of Le Fay's.
- Spoiled Brat: He is much more confident, rebellious, and louder than his siblings, which Robertina and Ex note.
Shuri Himejima is the human wife of Baraqiel and mother of Akeno Himejima. She was killed by her own parents due to Akeno's fallen angel blood, causing a rift between her husband and daughter's relationship.
- Adaptational Curves: Shuri is noticeably bustier, though still pretty average in size, in the anime.
- All Women Are Doms, All Men Are Subs: She used to engage in SM sessions with her husband.
- Death by Origin Story: Shuri is killed by her own family while protecting Akeno from harm.
- Generation Xerox: She resembles a grown-up Akeno down to the hair ribbons, but with a more modest chest and without the Hair Antennae.
- Heroic Sacrifice: She died protecting her daughter from enemies of Baraqiel, which turned out to be her own family.
- Like Mother, Like Daughter: She's revealed to have had a sadistic side to her. This later gets passed to her daughter.
- The Lost Lenore: She becomes one to Baraqiel after she was killed by the Himejimas.
- Miko: Shuri served as the family's shrine maiden back in the day.
- Missing Mom: Akeno's, because she's already dead.
- MuggleMage Romance: She has a romantic with Baraqiel, who is a powerful Fallen Angel, while Shuri is a human Shinto priest. Unfortunately, due to the Himejima family's low opinions against Fallen Angels, she is killed while protecting her daughter.
- Offing the Offspring: She's killed by her father while trying to protect Akeno.
- Oh, Crap!: She's utterly shocked when she realizes that her family has hunted her down.
- Posthumous Character: She dies before High School Dx D, when Akeno was still a child.
- Yamato Nadeshiko: A miko with the above trope looks the part but it gets weird when SM is added.
- You Shall Not Pass!: She had to stall the Himejimas to buy Akeno enough time to survive at the cost of her own life.
Tobio "Slash Dog" Ikuse
Tobio Ikuse is of the Longinus users of the fallen angel faction. He's revealed to be a distant relative to Akeno through his grandmother who was a Himejima.
- Aloof Big Brother: When he was first mentioned, he was said to hate Vali. Turns out, it's only because to Tobio, Vali's more of an Annoying Younger Sibling. Even he's surprised about the rumors of him hating Vali.
- Animal Motifs: Guess what it is. Also, his Longinus seems to be based on the Chinese legend of Tiangou, meaning "Heavenly Dog" .
- The Bartender: He works a part-time night shift as one at the Black Dog BAR.
- Canon Immigrant: He is the main protagonist of the prequel novel SLASH/DOG, also created by Ishibumi.
- Casting a Shadow: His Canis Lykaon (Also known as Dog God of the Black Blade) can attack through shadows, the shadow can only extend up to wielder's field of vision.
- Chekhov's Gun: The rosary that his grandmother gave to him which in turn he gave to Sae. It saves her from death.
- Dark and Troubled Past: 233 people, some of them being his classmates, died while they were going on a field trip, including his Childhood Friend. To top it all off, they were all transformed into Utsusemi and they're out to target people who didn't participate in the trip.
- Died in Your Arms Tonight: His childhood friend, Sae, pierced herself so that she could be free from the Utsusemi. Fortunately, she got better.
- Expy: Inverted as Issei is actually an expy of Tobio. Both were simple Ordinary High-School Student before being thrust into the supernatural world where in a short time, they quickly climbed up the power totem pole wielding powerful Longinus Sacred Gears and have multiple girls after them.
- From Nobody to Nightmare: He's an Ordinary High-School Student when he first starts off in SLASH/DØG. By the time he appears in High School D×D, Tobio's a powerful Longinus user who can force Vali into Juggernaut Drive.
- Hero of Another Story: Slash Dog is the name of Ishibumi's second light novel and more details about his story are found there.
- Long-Lost Relative: His Grandmother Ageha Ikuse was a memeber of Himejima clan. Making him Akeno cousin by blood.
- Master Swordsman: Given for the user of Canis Lykaon.
- Our Werebeasts Are Different: His Balance Breaker gives him the ability to transform into a humanoid black hound with six tails, enhancing his strength and speed by several orders of magnitude.
- Red Baron: Slash Dog which is also his Code Name and God of the Blade.
- Sole Survivor: One of the few who survived the tragedy thanks to him being sick on the day of the trip.
- Sinister Scythe: He's able to wield a Scythe thanks to the Canis Lykaon.
- Took a Level in Badass: From an Ordinary High-School Student into a guy who can force Vali to use Juggernaut Drive.
- Unwanted Harem: Played with. As of current volume of his home series, he has at least five girls wanting to be with him with poor dude being aware of it, yet he doesn't want it, at least at first. He really loves Sae, but Lavinia's wish of having a more playful relationship with him (which they later admit to be pointless), coupled with Natsume's determination to accompany him and Suzaku's insistence to marry him muddies his stance further. Time will tell if this sticks in Dx D.
Lavinia Reni is a witch in her twenties who is a member of Mephisto Pheles' magician group Grauzaberer (German for Gray Wizards).
- Action Girl: Moreso than Le Fay. She is a hands-on magician who will freeze her enemies without problem.
- Boobs of Steel: The Harem King Memorial art book listed her boobs size at 100 cm, surpassing the likes of Rias.
- The Chanteuse: Her cover with Tobio's team is that she is a lounge singer at the Black Dog Bar, where Tobio becomes the bartender and manager.
- Cool Big Sis: Issei, as well as both the Slashdog and Vali teams, agree that she is this, especially in regards to Vali himself.
- Hero of Another Story: Alongside Tobio, she is heavily featured in Ishibumi's previous work, Slash/Dog
- An Ice Person: Her Longinus, Absolute Demise (Also known as Eternal Ice Princess) is this, an independent avatar-type Sacred Gear taking form of a princess doll imbued with ice (hence her Ice Princess nickname). Its maximum range could freeze an entire small country.
- The Nicknamer: Gives males she is close with nicknames examples include Shark for Kouki, Toby for Tobio and Va-kun for Vali.
- Older Than She Looks: Issei mentioned that she looks like a twenty-year-old girl, but she is actually in her mid-to-late twenties. Keep in mind that she is at least eighteen by the time Slash/Dog takes place. Must be a witch's thing.
- Shameless Fanservice Girl: In Slash/Dog, she doesn't mind waking up in Tobio's bed with just a shirt on or inviting him to take a shower with her and Natsume.
- Sleepwalking: In Slash/Dog, it is shown that she suffers from this waking up in either Tobio's or Natsume's bed.
- Ship Tease: Between her and Tobio, at least at first. This is because Lavinia doesn't really want to make the relationship to be serious at first on account of her playful nature, but Tobio turned her down on the point of not wanting to make Sae feel uncomfortable (naturally, Sae considers this to be a competition). In Dx D proper, it remains to be seen, but their relationship appears to be on more cordial terms as Ishibumi seems to be playing up her relationship with Vali more.
Akeno's cousin and current head of the Himejima family.
- The Atoner: A lot of her objectives, including marrying Tobio, results from her wishing to fix a lot of Suou's actions, including bringing back exiled Himejimas, as exiling of them is what caused the Luxury Liner incident four months prior to SLASHDOG and two years before the start of Dx D.
- Boobs of Steel: As the head of the Himejima family she is a powerful mystic with an immense purification ability. She also ties with her cousin as having the biggest recorded breasts in the series at 102cm.
- Canon Immigrant: Like most characters involved with Tobio Ikuse, Suzaku originally appeared in SLASHDOG, Volume 2 after the Utsusemi Incident.
- The Chosen One: Was chosen by Suzaku, the Vermillion Bird to be its inheritor
- Hero-Worshipper: Was one for her aunt Shuri and was the only Himejima that had any kind of approval for Shuri's relationship with Barakiel. Her worship was such that she was distraut when news of Shuri's death and Akeno's exile came to her and started her path to atonement.
- Kissing Cousins: Intends to marry Tobio, her second cousin.
- Named After Someone Famous: According to tradition, being chosen by Suzaku the Vermillion Bird itself allowed Suzaku to take its name.
- Strong Family Resemblance: Despite the genetic impossibility due to Akeno's fallen angel lineage, Suzaku looks just like Akeno right down to their three sizes.
- Superior Successor: To her and Akeno's great-uncle. Where Suou can only summon a phoenix, though not an easy feat that, Suzaku has the ability to summon her namesake. Not only that, she is much more accepting of Akeno; that while she may not be able to bring her back into the family, she is nonetheless trying to mend bridges with her estranged cousin.