Characters in Unlimited Fafnir. Please be warned that this page contains spoilers, such as the very existence of the true dragons, and should be avoided unless you are up to date on the latest light novels.
The main character of the story, the only male D in existence. He joins Midgard at the beginning of the series.
- Abomination Accusation Attack: When Iris first meets Yuu, she fires these off like bullets out of a sub-machine gun. Considerng Yuu, a male, and a complete stranger, was on an all female island, sent there without warning or notice, and Iris was naked at the time note , her reaction is far more justified than most instances. Mitsuki, however, has considerably less justification when she does the same, especially when Yuu rushes into her bedroom as a result of hearing her scream.
- Above the Influence: Yuu tries really hard not to see Iris scantily clad, despite the latter being okay with it, after getting to know him. Initially, the inverse was true.
- Accidental Pervert: Considering the girls of Midgard aren't accustomed to having a male prescence on the island, Yuu frequently winds up stumbling upon situations where girls are underclothed.
- All Your Powers Combined: As the series goes on, he gains access to many different sources of power. At the beginning, he has his power as a D, assassin training from NIFL, Code Lost (a fragment of half of the eighth counterdragon), knowledge of a Atlantean weapon from Yggdrasil (said knowledge being part of the second true dragon), and is Neun, the ninth counterdragon. He gains Antigravity from killing Leviathan, Ether Wind from killing Hraesvelgr, receives more knowledge of Atlantean weapons from Yggdrasil, and gains the entirety of Code Lost (right before splitting most of it up with the others).
- Amnesiac Hero: Due to requesting knowledge from Yggdrasil for weapons to fight dragons, which takes up so much space in his brain that it erases some of his existing memories. At the beginning of the series, he can't even remember his parents. As he requests more knowledge from Yggdrasil, he loses more and more of his memories. It turns out that Yggdrasil was deliberately blocking out his memories as part of its efforts at gaining control over him. When Tia steals Yggdrasil's authority, Yuu gets his memories back.
- Chick Magnet: Like many male protagonists of Light Novels.
- Deal with the Devil: He makes one with Yggdrasil, receiving knowledge of Atlantean weapons in exchange for using them to fight their common enemy, the other dragons. However, the knowledge takes up so much space in his brain that it erases his existing memories each time he downloads it. Or rather, that's what Yggdrasil wants him to think. It actually made the deal with the intention of usurping control of his body, as a weapon to fight Angolmois.
- Declaration of Protection: Yuu does this to Iris. In a slight variation of the trope, he says if it comes down to it, he'll kill her himself to prevent her from turning into a dragon. Fortunately he doesn't need to do it after they manage to find a way to defeat the dragon attacking the school in episode 3.
- Freak Out: Yuu has one when he suddenly realizes he doesn't emotionally recognize Mitsuki as his sister anymore at the end of the fourth volume.
- Go Through Me: Yuu does this to protect Iris from getting killed by Mitsuki in episode 3.
- Gravity Master: After killing Leviathan, he inherits a weaker version of its authority. He can't use it directly, instead having to convert dark matter into antigravitational matter. He often channels the power through bullets, using these to reduce gravity, complete negate gravity or repel objects.
- Harem-Powered: Yuu is a "D", or a human born with the powers of a "Dragon", enormous Kaiju that select humans as "mates" and turn them into a matching "Dragon". Except later it's revealed that he's actually a "Counter-Dragon", and he also has the ability to "mate" with Ds. He thus "mates" with every girl in his school to protect them from being claimed by other Dragons.
- Heart Is an Awesome Power: Yuu's ability to summon a handgun seems a bit pitiful compared to the girls being able to cast devastating spells and attacks. However, said gun proves very useful against human targets.
- The One Guy: Yuu is the only male "D." However, he's not the only male counterdragon.
- Our Dragons Are Different: He is the ninth counterdragon, Neun.
- Power at a Price: Yuu is able to summon immense power capable of defeating dragons from Yggdrasil, but the blueprints of each new weapon comes at the cost of his memories. It then gets worse as he's only capable of remembering things that had happened during his time in the NIFL and nothing else about Mitsuki. Luckily, Tear hijacks Yggdrasil and slowly restores his memory.
- Soul Power: After killing Hraesvelgr, he inherits a weaker version of its authority. He can produce Ether Wind to manifest the souls of living things, paralysing them, or to listen to the thoughts of others. After being almost killed by Loki, he learns how to use Ether Wind on his own body. This makes him impervious to physical attacks and improves his reflexes (as his mind controls his body directly, removing the delays of transmitting information via the nervous system).
- Split Personality: Yuu can slip into one called "Fafnir", which gives him Super Reflexes and the ability to deal with nearly any human opponent.
- Take a Third Option: Yuu does this when he finds out they may have a way to defeat Leviathan coming after Iris in episode 3, rather than letting Mitsuki kill her, or letting Iris turn into a dragon.
- That Came Out Wrong: In the first episode, Yuu is questioned about his first meeting with Iris. He transmuted a wave of water to interrupt Iris's attempted attack. But the way she describes it, it makes him sound like a pervert trying to rip her clothing off, which doesn't help his situation any.
- Thou Shall Not Kill: Tries to avoid killing people at all costs, despite his training as an assassin. When he attacks Kili, he deliberately misses her vitals. Unfortunately, he unknowingly kills the Hreidmar soldiers, who were once humans. In Volume 10, he's forced to break this rule and lethally wound Loki in order to defeat him. However, Kili heals him afterwards.
- Tomato in the Mirror: He's actually Neun, the ninth counterdragon.
- Warrior Prince: In Volume 12, Firill tricks him into marrying her as Marduk flies over her country, making Yuu an example of this trope. Though thanks to the lack of documentation, this only applies when they're in Erlia's airspace or soil.
- Wave Motion Gun: Yggdrasil provides him knowledge of Atlantean weaponry, which he uses as a trump card against dragons. Due to his low dark matter generation capacity, he can't construct the weapons on his own, needing to borrow the dark matter of others.
- Weak, but Skilled: Combined with Master of None. He is not able to use any of his inherited authorities to their full potential, has the lowest dark matter generating capacity, and is a human-sized counterdragon rather than a Kaiju. However, he's still a good strategist and is skilled at anti-personnel combat.
- Winds of Destiny, Change: Downplayed. Yuu has enough of Code Lost to know the optimal actions required to defeat human opponents, but he doesn't have enough of the authority to manipulate luck.
A member of Brynhildr Class and of the Dragon Subjugation Squad, Iris is the very first person Yuu meets on Midgard. After killing Basilisk, Iris inherits its authority.
- And Then John Was a Zombie: Due to inheriting Basilisk's complete authority, she starts changing into a new Basilisk. Her power is vastly greater than any other D who's inherited a dragon's authority, even exceeding the original Basilisk's, but her body becomes increasingly inhuman over time. Thankfully, this is reverted when Yuu transforms her into Neun.
- Because You Were Nice to Me: Iris says this to Yuu in episode 2, stating he's nicer to her than the other girls have been so far, hence why she trusts him.
- Body Horror: When she starts transforming, red diamond scales appear on her body.
- The Ditz: Definitely. Not many people would forget to put on panties in the morning. In many ways, she behaves like the younger Tear.
- Driven to Suicide: Iris seriously contemplates jumping off the school roof to avoid turning into a dragon during episode 2. Fortunately she's too scared to actually follow through, and Yuu helps reassure her that he'll protect her.
- One-Winged Angel: To gain the strength to fight Kraken Zwei, she deliberately lets her body transform further into Basilisk. It reaches the point where her eyes become red and she can fire Catastrophe from them.
- Our Dragons Are Different: She gradually transforms into Basilisk after inheriting its authority. This transformation is overridden when Yuu marks her as a mate, turning her into another Neun. However, she still retains Basilisk's authority, albeit she now has to use it through dark matter like the other Ds who've inherited a dragon's authority.
- Reluctant Fanservice Girl: Her very first appearance has her completely naked due to her swimsuit washing away.
- Stuff Blowing Up: Any dark matter she tries to transmute (except for her fictional armament) explodes. At Yuu's suggestion, she weaponizes this as a powerful attack.
- Super Speed: When partially transformed into Basilisk, she can move fast enough that human eyes can't keep up with her.
- Super Strength: When partially transformed into Basilisk, she can easily lift rubble off of herself and trade blows with Kraken Zwei.
- Suspiciously Specific Denial: Iris forgets to put on panties in episode 4. When she sees Yuu, she tries to explain in such a way that she was totally Going Commando just for that day, and not because she forgot.
- Time Master: She inherits Basilisk's authority after killing it. She can use Catastrophe, but has yet to be shown using Basilisk's precognition.
- Unskilled, but Strong: Iris's attempts at any Dark Matter transmutation results in an explosion, which causes her to get blown up by her own powers. Though she manages to take advantage of this when Yuu suggests transmuting at a distance.
Yuu's older sister by adoption, the Student Council President of Midgard and the captain of the Dragon Subjugation Squad. Prior to the beginning of the series, her parents were killed in a car accident and she was adopted by Yuu's parents.
- A-Cup Angst: When Yuu has to cross-dress to disguise himself from his parents, Lisa suggests using pads to increase his feminine charm, which angers Mitsuki.
- Antimatter: An authority gained from Kraken, which she uses in the form of an arrow. Interestingly, unlike other Ds who've inherited authorities, she gained hers before killing Kraken - the newly-dragonified Miyako bestowed a portion of the authority to Mitsuki so that she could kill the first Kraken and Mercy Kill her.
- Childhood Friend: To Yuu.
- Energy Bow: Mitsuki uses one as her fictional armament.
- Father, I Want to Marry My Brother: A young Mitsuki says this to Yuu in a Flash Back during episode 2. However, they weren't yet siblings yet at that point (Mitsuki was adopted into the Mononobe family after her parents died in a car crash).
- Insecure Love Interest: Mitsuki fears that the only reason Yuu cares for her is because of his instincts as the 9th Counterdragon, which causes him to want to protect the seal(her) on the 9th True Dragon.
- Not Blood Siblings: She and Yuu became siblings by adoption after her own parents' deaths.
- Our Dragons Are Different: She becomes one of Yuu's mates and hence another Neun.
- Oxymoronic Being: The true dragon Angolmois is sealed in her prior to the start of the series. She then gets turned into another Neun, the counterdragon meant to seal this particular true dragon.
- Shoot the Dog: She was forced to kill her best friend, Miyako, after the latter was dragonified by Kraken.
- These Hands Have Killed: Mitsuki had to kill a fellow D, Miyako, two years prior to the start of the series, something she's not happy about.
- Tomato in the Mirror: She is the host of Angolmois, but is unaware of this until the end of Volume 10.
A member of Brynhildr Class and of the Dragon Subjugation Squad, Lisa is the daughter of the prestigious Highwalker family.
- Arranged Marriage: Her parents have a list of preferred suitors lined up, and the only choice they offer her is to pick from the list. At least until the end of Volume 5, when they decide that Yuu is an acceptable candidate.
- Blade on a Stick: Her fictional armament, Gungnir.
- Defrosting Ice Queen: Lisa is cold towards Yuu at first, but opens up to him slightly after he helps them defeat a dragon. But instead of calling him a family member like she does with the other students, she "upgrades" him to "probationary classmate."
- Frickin' Laser Beams: One of her main attacks, which she shoots from the tip of Gungnir.
- Our Dragons Are Different: She becomes one of Yuu's mates and hence another Neun.
- Team Mom: She's the one who looks out for her classmates' wellbeing the most.
- Tsundere: To Yuu. She starts off as a Type A and shifts to a Type B later on.
- Why Did It Have to Be Snakes?: She doesn't like haunted houses.
A member of Brynhildr Class and of the Dragon Subjugation Squad, and a princess of the Principality of Erlia.
- Badass Bookworm: She's almost always engrossed in a book, and her fictional armament is one as well.
- Deadpan Snarker: Firill will often comment about stuff Lisa says or does towards Yuu, such as when she mentions that Lisa spent a lot of time picking out a swimsuit to show off to him.
- Happily Married: She gets married to Yuu in Volume 12, albeit the marriage is only applicable within the Principality of Erlia's borders.
- Harem Seeker: An unconventional example. She offers to marry all of Yuu's other love interests in addition to him so that they can all be together (as her country allows same-sex marriage and, for royalty, polygamy).
- Our Dragons Are Different: She becomes one of Yuu's mates and hence another Neun.
- Royals Who Actually Do Something
- The Tease: Out of all the heroines, she's among the most open with her affections towards Yuu.
- Tome of Eldritch Lore: Her fictional armament Necronomicon.
- Why Did It Have to Be Snakes?: She doesn't like thrill rides like roller coasters.
A member of Brynhildr Class and of the Dragon Subjugation Squad, and Ren's older sister by adoption.
- Big Sister Instinct: She's very protective of Ren.
- Dark and Troubled Past: She grew up in a country frequently wracked by conflict. Death was an everyday occurrence, to the point that Hraesvelgr visited multiple times to consume the numerous souls (with her family's souls among them). She joined an anti-dragon organisation, fueled by her hatred towards dragons. However, her powers as a D awakened, and she was now loathed by her former comrades. They sold her to Kenya Miyazawa as a test subject. Ironically, this was more pleasant than her previous life, as she wasn't particularly mistreated and was able to form a close bond with Ren. When Ren's powers manifested, Ariella ran away with her to avoid Kenya's experiments.
- Fantastic Racism: She hates dragons due to Hraesvelgr eating the souls of her family.
- Kung-Fu Wizard: She's skilled at hand-to-hand combat and as a D.
- Luckily, My Shield Will Protect Me: Her fictional armament, Aegis.
- The Mole: She's actually a spy for NIFL, and passes information to them for most of the series. This is no longer the case as of Volume 10.
- Our Dragons Are Different: She becomes one of Yuu's mates and hence another Neun.
- Secret Keeper: She's the first to figure out that Jeanne is actually a girl, and keeps the secret for four more volumes.
- She's Got Legs: Yuu compliments her on her legs, to her embarassment.
A member of Brynhildr Class and of the Dragon Subjugation Squad, and the daughter of Kenya.
- Child Prodigy: Downplayed, but she's smart enough to skip several classes and get into Brynhildr Class.
- Cute Bruiser: Despite her small size, she had the highest dark matter generation capacity of all Ds and can dish out extremely powerful attacks.
- Drop the Hammer: Her fictional armament, Mjolnir.
- Elective Mute: Early in the series, she types on her personal terminal instead of talking to people. This changes when she grows more confident.
- Our Dragons Are Different: She becomes one of Yuu's mates and hence another Neun.
- Shrinking Violet: It takes several volumes before she opens up to Yuu.
A member of Brynhildr Class and of the Dragon Subjugation Squad, who first appears in Volume 2.
- Akashic Records: She can access this after gaining Yggdrasil's power. This is how she discovers the existence of the true dragons.
- Berserk Button: Tear gets rather upset in episode 4 when Mitsuki insists she's a human, not a dragon. She nearly destroys the auditorium in the process.
- Dark and Troubled Past: When her powers first awakened as a child, her parents had her create gemstones to make them wealthy. This led to them being kidnapped by a criminal organisation, though Yuu freed them. Eventually, her parents tried to sell her off, but an anti-dragon organisation attacked the family. Kili rescued Tear and indoctrinated her into thinking she was a dragon, in order to serve as a dragon's mate.
- The Glomp: Tear does this to Yuu in episode 4 after seeing him at the school and continues to cling to him in several later scenes.
- Green Thumb: Yggdrasil's authority allows her to create vines which are capable of sealing the dark matter generation of those bound by them.
- Hijacking Cthulhu: Tear ends up stealing Yggdrasil's authority by using her horns, which were upgraded by Kili.
- Horned Humanoid: She has two tiny red horns growing from the sides of her head. Kili used biogenic transmutation to give her these, to let her take over Yggdrasil.
- Mysterious Waif: Tear is highly sought after by a dragon cult, due to her being chosen as Basilisk's mate.
- Our Dragons Are Different: She's now the new core of Yggdrasil. She later becomes one of Yuu's mates and hence another Neun.
- Rescue Romance: Tear is rescued by Yuu from some gangsters in episode 4. When she sees him again, she immediately declares herself to be his wife.
- Shock and Awe: By taking over Yggdrasil's authority, she has inherited its control over electricity.
Kili Surtr Muspelheim
A mysterious "D" and the leader of the Sons of Muspell, a terrorist cult that reveres dragons. She starts as an antagonist, but eventually joins Class Brynhildr.
- Adaptational Villainy: Zigzagged in the anime. She's more brutal towards Lisa when defeating her and actually threatens Tear, but in later appearances, she admits to nearly Becoming the Mask.
- Artificial Human: She was created by Vritra out of dark matter, to become Hraesvelgr's mate.
- Clingy Jealous Girl: She possessive of Yuu to the point of reviving Loki. In her mind, Yuu's guilt over killing Loki means he's thinking of his former CO more than her.
- Dating Cat Woman: Kili has no problems on hitting with Yuu, who doesn't reciprocate until after her HeelFace Turn.
- Green Rooming: In the anime at least due to the reveal happening later. As the student, Honoka, she's mostly out of the spotlight until her true identity is revealed.
- Healing Hands: She can use biogenic transmutation to heal wounds, though this is less effective on other people (as she's not as familiar with their bodies).
- HeelFace Turn: After an Enemy Mine to defeat Yggdrasil, she takes the class's side over her mother's.
- Kick the Son of a Bitch: Tear's parents were still exploiting her powers, causing Kili to kill them rather than save them from their wounds.
- Master of Disguise: She can alter her own body with biogenic transmutation, changing her appearance and even her biometric information.
- Meaningful Name: Surtr is the king of the fire giants in Norse Mythology, and Muspelheim is the realm he rules over.
- Playing with Fire: Her specialty. She usually creates a zone of dark matter particles around herself, which she calls Muspelheim. She can transmute this into fire and heat to attack anything within range, and to intercept any attack directed at her.
- Well-Intentioned Extremist: She believes giving Tear to Basilisk is the best way to ensure her safety and to spare Midgard from the counterdragon.
Charlotte B. Lord
The principal of Midgard and the current wielder of Code Acht, also known as "Gray" Vampire.
- Assimilation Plot: The purpose of Code Acht is to assimilate all of humanity, keeping them from destroying the environment with their technology. Charlotte herself doesn't want to take over all of humanity, though she'll use her authority to stifle conflicts in the world, at least until she nearly loses control of it.
- Blood Magic: Her powers work through her own blood.
- Bunny-Ears Lawyer: Despite her ogling of the students, she's still a counterdragon and is capable of assimilating NIFL soldiers when they try to invade the island.
- Dirty Old Woman: She licks Yuu's hand to check his dragon mark, and then immediately suggests that he go with her to peek on the girls during their physical. Micah, her assistant, promptly puts a stop to that.
- Healing Factor: She has a powerful one, and can spread it to others who ingest her blood.
- If It's You, It's Okay: While she's normally attracted to females, she does express an interest in Yuu that seems to be more than just platonic.
- It Sucks to Be the Chosen One: Due to her authority, she's pressured to serve the interests of other nations and she's a target for NIFL due to the dangers of her power.
- Older Than She Looks: She looks much younger and is shorter than Yuu, who is sixteen.
- Omnidisciplinary Scientist: On top of being the principal of Midgard, she's a medical doctor and a scientist specializing in dragons.
- Our Vampires Are Different: She doesn't have any of the usual vampire weaknesses: sunlight doesn't harm her (but it causes her to tan unnaturally fast, so she avoids it to hide her true nature) and she doesn't need to drink blood. In fact, her abilities require others to take in her blood.
- Tactical RockPaperScissors: Her ability lets her control humans, but it's useless against machines or other counterdragons.
- Walking Spoiler: She's a humanoid counterdragon, which is itself a big hint that Yuu is one as well.
A major in NIFL, and Yuu's former superior officer.
- Armchair Military: Invoked. He prefers to stay behind a desk despite his considerable combat skill and mastery over Code Lost because he doesn't want to become a sacrificial pawn like his father. He only decides to do the deed himself when all Code Lost users are unwilling or unable to kill Charlotte.
- Awesome Mccoolname: Combined with Names to Run Away from Really Fast and Meaningful Name. His first name is the same as the Norse trickster god and he is indeed a Manipulative Bastard.
- Boomerang Bigot: Loki displays animosity towards authority holders in general (including Ds) for being potential threats to the humanity, which is why he ends up trying to destroy Midgard along with Charlotte. When he dies, he admits that with his Code Lost, he was also a dangerous "monster" whose power would only be used for evil.
- The Chessmaster: He planned a Xanatos Gambit to disperse both Code Acht and Code Lost whether or not he survives his duel with Yuu. He also has his army ready to blow up the island no matter what the outcome, though Tear put a stop to that with Code Zwo.
- Faux Affably Evil: The first few pages of the manga pretty much establish Major Loki as this trope. He has Yuu bound and gagged while politely asking if he wants to join NIFL, and then grabs his head and forces him to nod.
- A Good Way to Die: When mortally injured by Yuu, he's perfectly fine with it, as this will result in Yuu gaining the full authority of Code Lost.
- Heroic Lineage: It is eventually revealed that he is the descendant of "Colorless" Fafnir, the counterdragon created to oppose the threat of humanity through killing.
- Ho Yay: Many of his interactions with Yuu have undertones of this. A good example is when he notices that Yggdrasil has laid claim to Yuu, and declares that Yuu is his.
- Missed the Call: Loki was unable to inherit his father's authority due to being in his mother's womb while the authority was looking for a new wielder, resulting in that power being spread to random individuals. Though he proves to have excellent compatibility with Code Lost once he kills most of the other wielders to inherit most of the authority.
- Personality Powers: Loki, the one most suited to Code Lost, is a ruthlessly pragmatic "hero" who often thinks that Murder Is the Best Solution to save the world.
- Well-Intentioned Extremist: Ultimately, his goal is to free humanity from Charlotte's control, no matter the cost.
- Winds of Destiny, Change: His power when he gains access to Code Lost. He can alter causality to kill any human (for example, he makes a drone explode in such a way that a piece of shrapnel kills one specific person) and to prevent his own death.
HreidmarA strange figure who serves as Loki's bodyguard and was formerly Yuu's mentor.
- The Dreaded: When first encountered, Yuu treats him as an enemy he has no hope of defeating.
- The Faceless: Always fully covered in a armor. Underneath, they don't actually have a face, or a body.
- No Name Given: "Hreidmar" is a code name for a group of people who have been implanted with Code Lost, and none of their real names are known.
- 24-Hour Armor: He's never seen outside his armor. This is because the Hreidmars' bodies are unstable, and if the armor is breached, they leak from it in the form of smoke.
Jeanne HortensiaThe sniper of Sleipnir, known for her incredible eyesight, and Yuu's former subordinate. She disguises herself as a boy under the name of John.
- Badass Normal: A normal human who can fight on par with Ds. Subverted, when it turns out that she's descended from Atlantean soldiers and has inherited their genetic enhancements.
- Bifauxnen: To the point that when she becomes a student of Midgard, she routinely faces hordes of fangirls.
- Enemy Mine: She's forced to work with Kili in order to investigate a threat to Yuu.
- Friendly Sniper: She specializes in sniping due to her eyesight.
- Hidden Buxom: When she dresses as a girl, she's revealed to be stacked, much to Mitsuki's chagrin.
- Samus Is a Girl: She disguises herself as a boy in order to fit into Sleipnir.
- Super Senses: She's renowned for her extremely keen eyesight. Both her visual acuity (ability to discern details at long distances) and kinetic vision (ability to track moving objects) are far above the average.
- Walking Spoiler: Her actual gender is revealed in the same volume she's introduced. It's hard to discuss her at all without spoiling this.
KrakenA dragon made of mithril and covered in tentacles, with the ability to shoot antimatter projectiles. It attacked Midgard two years prior to the start of the series, but was killed by Mitsuki.
- Antimatter: It could shoot antimatter projectiles from its eye, which are capable of annihilating any target.
- Face Full of Alien Wing-Wong: It transformed Miyako into another one of its own kind and impregnated her with what would eventually become Kraken Zwei.
- Gaia's Vengeance: It was created to oppose the sixth true dragon, Nyarlathotep.
- Hoist by Their Own Petard: It was killed by Mitsuki using a portion of its own antimatter power. Taken further when it's revealed that it had transformed Miyako into another Kraken, only for her to grant Mitsuki the authority that allowed her to kill both Krakens.
- Red Baron: "Purple" Kraken.
- Takes One to Kill One: Its mithril body made it resistant to most attacks, but it could be harmed by others with the power of antimatter. Kraken was originally created in order to oppose Nyarlathotep, which was also a tentacled monster made of metal.
LeviathanA colossal dragon with power over antigravity, considered to have the strongest defense among dragons. It is the main antagonist of Volume 1.
- Expy: To Sin from Final Fantasy X. Both are enormous whale-like monsters with some reptilian features, which have the power to control gravity (and use this to levitate their bodies).
- Gaia's Vengeance: It inherited its authority from "Silver" Tiamat, which was originally created to oppose its correspondign true dragon.
- Gravity Master: It can levitate its massive body and create repulsive antigravitational fields. The latter can be deployed to block attacks (even lasers, since gravity can also bend light) or fired as a destructive projectile.
- Kaiju: Among the larger counterdragons. Only Yggdrasil surpasses it in size.
- Nigh Invulnerable: Not only does it have nearly-impenetrable barriers, its massive body allows it to soak up an enormous amount of injury and still keep going.
- Red Baron: "White" Leviathan.
HekatonkheirA dragon resembling a giant covered in blue scales, with a horn instead of a head.
- Action Bomb: Vritra has it approach Yggdrasil and explode, in a failed attempt to kill Yggdrasil.
- Complete Immortality: Its main power. No matter what damage is done to it, it will regenerate. Even if its entire body is destroyed, it will revive eventually. This trait is because Vritra can simply remake it using dark matter.
- Energy Being: It is not actually a counterdragon, but is a dark matter construct made by Vritra - essentially her fictional armament.
- Meaningful Name: It's named for the Hekatonkheires, three giants in Greek Mythology who each had a hundred hands and fifty heads.
- Red Baron: "Blue" Hekatonkheir
- Rubber Man: It is capable of stretching its limbs.
BasiliskA dragon resembling a giant lizard, covered in scales of red diamond. It is considered to have the greatest offense among dragons due to its power, Catastrophe. It is the main antagonist of Volume 3.
- Beam Spam: The red Basilisk utilizes beams that have a weathering effect on anything it hits.
- Combat Clairvoyance: Basilisk can see into the future, though it can't predict everything perfectly.
- Cooldown: Its third eye's attack is extremely powerful, but can only be used continuously for five seconds. It then has to wait before using it again, though it can still use the normal Catastrophe in this time.
- Gaia's Vengeance: It was originally created to destroy the fifth true dragon Bahamut.
- Gemstone Assault: It can launch its diamond scales as projectiles, but only when desperate as this reduces its defenses.
- Glass Cannon: Only relative to other dragons. It has the most powerful attack of all of them, but isn't especially durable, and survives by intercepting any attacks directed at it.
- Meaningful Name: Named for the legendary reptilian monster with a lethal gaze.
- Red Baron: "Red" Basilisk.
- Tactical RockPaperScissors: Catastrophe allowed it to completely destroy Bahamut, despite the latter's quick regeneration, by forcing its cells to undergo apoptosis.
- Time Master: Its main power, Catastrophe, is a red beam shot from its eyes that ages the target two thousand years every single second. It can fire an even more powerful version from its third eye, which has twice the range and ages the target hundreds of millions of years. The third eye's beam can rapidly degrade even mithril, and can pierce through an entire mountain. Additionally, Basilisk also possesses the power to see the future (though the future it sees can change due to the unpredictability of living things).
- Walking Wasteland: As it moves, it sweeps the ground in front of it to destroy any traps in its path.
HraesvelgrAmong the smaller dragons, Hraesvelgr resembles a giant eagle or other bird of prey. It constantly flies at high speed, and is considered to be invincible as no attacks can affect it. It is the main antagonist of Volume 4.
- Feathered Fiend: It resembles a giant bird.
- Meaningful Name: In Norse Mythology, Hraesvelgr is a giant in the form of an eagle which creates wind by flapping its wings.
- Nigh Invulnerable: Even more than other dragons. The other dragons can at least be damaged to some extent, but Hraesvelgr is wholly unaffected by any attack. This is thanks to its ability to materialize its soul outside its body. Only Noah, an Atlantean weapon that fires concentrated thoughts, can harm it.
- Red Baron: "Yellow" Hraesvelgr.
- Soul Power: It has the power to materialize souls, using this to paralyze its victims. It is also known for visiting areas where many deaths take place and consuming the souls of the dead. Its invulnerability is due to using this power on itself, manifesting its soul outside its physical body. As souls operate on different laws to normal matter, its soul acts as impenetrable armor.
VampireSee Charlotte B. Lord under the "Midgard" folder.
YggdrasilA dragon resembling a giant tree. Prior to the beginning of the series, it makes a deal with Yuu, offering him knowledge of Atlantean weapons in order to fight their common enemies - the other counterdragons.
- Akashic Records: The name of Yggdrasil's authority. It allows it to access all information sensed by the plant life of Earth, making it practically omniscient.
- Anti-Villain: Yggdrasil is one of the most selfish characters in the series, but its fear of death is sympathetic considering what its predecessor went through.
- Deal with the Devil: It's the devil in its deal with Yuu by providing ancient technological blueprints in exchange for memories. This will eventually allow it to take over Yuu.
- It's All About Me: It knows that Yuu is Neun and wants to take control of him to serve as a weapon to fight Angolmois. It also wants Yuu to kill all the other counterdragons so that it can eventually monopolize all the authorities, making it the sole survivor of the upcoming apocalypse.
- Laser-Guided Karma: Its attempts to hijack Yuu leads to Tear taking it over and stealing its authority.
- Nigh Invulnerable: While its current body can be destroyed with sufficient firepower, Yggdrasil can simply transfer its consciousness into another plant. This makes it impossible to outright kill it without destroying all plants on Earth, which would obviously lead to the extinction of all other life on Earth (barring chemosynthetic organisms).
- Nothing Is Scarier: It inherited the memories of Kiskanu and is terrified of its predecessor's last moments, where it slowly lost all thought processes as all the planet's plants died. The fear of the same thing happening to it fuels its selfish desire to survive, all other counterdragons and life forms be damned.
- Shock and Awe: As part of its control over information, Yggdrasil can manipulate electricity. This allows it to hack into and control machines, which was originally used to destroy Atlantis' technology and civilization. It also allows it to hijack dark matter, as it can send out more powerful electrical signals than the thoughts that Ds or Vritra use.
- Tactical RockPaperScissors: Its power over electricity makes both machines and dark matter a liability against it. This allowed its predecessor Kiskanu to destroy Atlantean civilization, and Yggdrasil to gain the upper hand over Vritra.
- They Know Too Much: Once Lisa gets wise to Yggdrasil's plan to bodyjack Yuu, the tree tries to kill her and destroy Midgard.
- World Tree: Its name and appearance is a reference to the world tree, Yggdrasil.
VritraThe first dragon known to humans, who appeared 25 years prior to the start of the story, with power over dark matter. She is the only one to actually have the conventional form, appearing as a black western dragon.
- Big Bad: Subverted. She is the origin of Ds and the "mother" of Kili. Vritra created the Type Dragon system, which allows other counterdragons to mark Ds and turn them into mates. However, this was done in order to increase the number of counterdragons to prepare for Angolmois, the real Big Bad.
- Blue and Orange Morality: She doesn't understand why humans don't want to transform into counterdragons and she honestly believes she's doing them a favor with her Type Dragon system.
- Cute Monster Girl: Her usual appearance is a girl of the same apparent age as Tia, with a strong resemblance to her daughter Kili.
- Easily Forgiven: Averted. Even with the revelation that she's Good All Along, the protagonists are understandably wary of her for causing the other Counterdragons to appear, which resulted in a lot of destruction for human civilization.
- The Extremist Was Right: On one hand, Vritra's plan to turn humanity into Counterdragons resulted in a lot of death and destruction, especially to some of the protagonists' families. On the other hand, all those previous authorities turned out to be necessary due to the 9th calamity reviving several of its predecessors, which can only be killed by corresponding Counterdragons. Downplayed in that she didn't initially know that the older True Dragons would come back.
- A Form You Are Comfortable With: She takes on a human form to converse with Tia, the new Yggdrasil.
- Golem: Technically, all of her bodies are this, as her real form exists in a higher dimension.
- Hazy Feel Turn: Invoked by the protagonists. Vritra's human avatar gives them advice on the 9th true dragon, but they still suspect she may try to revitalize her own plans to transform humanity.
- Hoist by Her Own Petard: Vritra created the Type Dragon system to transform people into counterdragons. This also applies to Yuu, who mates with his classmates and turns them into the same counterdragon as him, which doesn't transform them because he's physically a human being too. He also mates with the only other counterdragon who could do the same, which means only his kind can spread rather than the Kaiju that Vritra originally intended. This trope might be subverted considering that Code Neun is geared towards stopping the 9th true dragon, which was her intended result in the first place.
- Imagination-Based Superpower: Like Ds, she can create and transmute dark matter (more accurately, Ds have fragments of her authority). Her dark matter capacity is orders of magnitude above any D's - she can create a giant meteor as an attack, and once recreated the entire Earth after it was destroyed by the seventh calamity. She is also capable of biogenic transmutation, allowing her to create Hekatonkheir, Kili and the dragon body that most people believe to be Vritra. However, even her power has limits. She claims that dark matter is limited in quantity, which is why she can't recreate the entire planet again. She also had to expend a great deal of effort to create Kili, and she has trouble getting the taste right when transmuting food.
- Meaningful Name: "Vritra" is a dragon in Hinduism.
- Physical Goddess: She once had the power to recreate the planet, though in the present, she's not capable of doing it again.
- Puny Humans: She views humans as weak and powerless, and thinks it would be better for them to all become dragons. However, she does become interested in human foods and entertainment.
- The Smurfette Principle: The only female among the counterdragons, prior to Kraken Zwei's birth.
- Walking Spoiler: The fact that Vritra usually appears in the form of a human girl is one of the least spoileriffic things about her.
- Well-Intentioned Extremist: Her actions are all to prepare the planet for the oncoming ninth true dragon. Turning the entire human population into counterdragons is a perfectly acceptable action, in her view.
- Supernaturally Young Parent: She's considered to be Kili's mother, and is presumably very old, but appears as a girl several years younger than Kili.
Kraken ZweiThe daughter of Kraken and the dragonified Miyako, a D-counterdragon hybrid. While still incubating in Miyako's remains, she was kept dormant in Kenya's laboratory for most of the series. Yggdrasil's attack disabled the laboratory's systems, allowing her to awaken in Volume 7.
- All Your Powers Combined: She has the powers of both a D and a dragon (specifically Kraken). She later gains Code Neun as well after Yuu transforms her.
- Antimatter: She can fire antimatter projectiles from her eye, due to inheriting Kraken's authority.
- Cute Monster Girl: Due to her hybrid nature, she appears as a young girl with long mithril strands for her. After being transformed into another Neun, her hair is now normal, making her indistinguishable from a human.
- Half-Human Hybrid: While both her parents were physically dragons, she nevertheless inherited human traits from her mother.
- Imagination-Based Superpower: Being half-D allows her to control and transmute dark matter. Her draconic half means that she's even capable of biogenic transmutation.
- Mithril: Her hair is made of this, similar to the Kraken's tentacles. This is no longer the case when she's transformed into another Neun.
- Prehensile Hair: Her mithril hair is as mobile as a cephalopod's tentacles, and can be used to both attack and defend.
- Walking Spoiler: Her very existence spoils the fact that counterdragons transform Ds to mate with them, and that Kraken did this to Miyako.
- You Gotta Have Blue Hair: Her hair is silver due to being made of mithril. It becomes purple after Yuu turns her into another Neun.
FafnirThe brother of Leonardo B. Lord and the original wielder of Code Lost.
- Antagonist Title: Subverted. His name is in the series's title, but he's long dead and his backstory paints him as a neutral character.
- Cain and Abel: Averted. He never interfered with his brother, though his descendants are more willing to kill holders of Code Acht.
- Posthumous Character: Unlike his brother, he doesn't have an eternal lifespan.
- Refusal of the Call: Despite his purpose to kill off humanity, he instead chooses to never use his power.
- Satellite Character: He has almost no characterization due to being long dead and his role in the story is to establish where Code Lost originated from.
NeunSee Yuu Mononobe under the "Midgard" folder.
AtlantisAn ancient civilization of alien humanoids who were deemed a threat due to their technology.
- Advanced Ancient Humans: The citizens of Atlantis are the ancestors of humanity and possessed extremely advanced technology.
- 0's and 1's: A bizarre example exists in Atlantis's artifacts. When Kiskanu shut down all their technology, the Atlanteans decided to save as much of it as they could by carving their governing Machine Intellect program's binary into stone tablets. NIFL later uses this binary to create Atla, a weaker version of the original Machine Intellect.
BahamutThe fifth true dragon. Originally killed by Basilisk, it is resurrected by Angolmois in Volume 12.
- Beam Spam: Due to its power to absorb heat, it can also release it in the form of beams.
- Energy Absorption: "Eternal Longevity" Bahamut is capable of absorbing thermal energy and using it to regenerate and attack.
- From a Single Cell: It has incredibly powerful regeneration, to the point that concentrated firepower by NIFL doesn't even come close to killing it. Only Basilisk's Catastrophe can do so, and even then it requires the third eye's version of the power.
NyarlathotepThe sixth true dragon. Originally killed by Kraken, it is resurrected by Angolmois in Volume 12.
- Nigh-Invulnerability: In terms of raw durability, it is unquestionably the toughest entity in the series. Even Basilisk's third eye barely fazes it. Only Kraken's antimatter, which destroys anything made of matter no matter how tough it is, can defeat it.
ApocalypseThe seventh true dragon.
- Apocalypse How: True to its name, its successfully destroyed the entire planet in the past. Vritra had to recreate the planet using dark matter afterwards.
HumanoidThe eighth true dragon, humanity itself. It (obviously) was not destroyed like the other true dragons, but was instead controlled and manage by Charlotte using Code Acht.
- Humans Are Cthulhu: Gaia itself considers human technology a threat comparable to many of the Eldritch Abominations listed in this folder, to the point of creating two authorities to counter it.
AngolmoisThe ninth true dragon. It was sealed in Mitsuki by Yuu prior to the start of the series. However, it breaks free at the end of Volume 11.
- Big Bad: As the currently active and most dangerous True Dragon, it's seemingly the main antagonist of the series. It's the main reason Yggdrasil and Vritra do anything villainous, since they're trying to oppose it in their own ways.
- Sealed Inside a Person-Shaped Can: During the incident that killed Mitsuki's parents, Yuu sealed Angolmois inside of her. Unfortunately, her insecurities cause the seal to weaken.
- Shapeshifter Guilt Trip: It can take the forms and personalities of Mitsuki's loved ones, including Miyako, to manipulate her. Mitsuki is fully aware of its true nature, but maintains an uneasy alliance with it nonetheless.