Loki Jotunheim
Loki Jotunheim
Vital statistics
Name Loki Jotunheim
Kanji ロキ・ヨトゥンヘイム
Romaji Roki Yotunheimu
Gender Male
Birthdate November 21
Affiliation NIFL
Status Alive
Occupation Major
Relatives 'Colorless' Fafnir (Ancestor) †
Unnamed Father †
Leonardo B. Lord (Distant Relative) †
Charlotte B. Lord (Distant Relative)
First appearance
Light Novel Debut Volume 1
Manga Debut Chapter 1
Anime Debut Episode 2
Seiyuu Nobuyuki Hiyama

Loki Jotunheim (ロキ・ヨトゥンヘイム, Roki Yotunheimu) is a former main antagonist in the Unlimited Fafnir series. He is a high-ranking military officer at NIFL, holding the rank of Major, and Yuu Mononobe's former superior officer during the latter's time as a NIFL soldier. He is also the one responsible for the implantation of the Fafnir persona in Yuu.


Loki is portrayed as a young man with silver hair and blue eyes. In the manga, he appears to have slit pupils. He is usually clad in NIFL's military uniform.


Loki has been shown to be a cunning person with a duplicitous and manipulative nature, who always schemes behind the scenes to achieve his desired result. He is also quite ruthless, as he believes that all Ds whose dragon marks change color must be exterminated immediately before they have a chance to become Dragons. He also showed no hesitation in training Yuu to become the most efficient killer possible, despite his young age, or killing hundreds of people to complete Code Lost, further showcasing his callous nature. However, at the core of his actions lays his desire to become a true hero by freeing the world from 'Gray' Vampire's control no matter the cost so that humans can keep fighting for their freedom against oppressive regimes.


Loki was born as the son of a man who was descended from Leonardo B. Lord's older brother, 'Colorless' Fafnir, a Counterdragon born for the purpose of killing mankind. Due to his father's action of killing Leonardo, Loki became known as the 'son of the hero' in NIFL and everyone had high hopes that he would also become a hero by killing Charlotte B. Lord, thus ridding the world of the 'Gray' Vampire's control. However, due to the fact that his father was killed while he was still in his mother's womb, Loki did not inherit the Authority of 'Colorless' Fafnir. As such, he began experimenting with humans who had inherited Code Lost in order to discover a way to eliminate the current 'Gray' Vampire. Three years before the start of the series, Loki met with Yuu Mononobe after the latter repelled Hekatonkheir with his power. Because of Yuu's potential, along with the loss of memories and emotions which made him ideal for manipulation, Loki forced him to become his subordinate and implanted Code Lost inside him with the purpose of making him the strongest assassin and using him as a weapon against the Ds and Charlotte. Over the course of three years, Loki sent Yuu and his team, Sleipnir, on various missions across the globe in order to have Yuu become the complete Fafnir, but was unable to finish him up before Yuu was reassigned to Midgard as a student.


Dragon's EdenEdit

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Loki contacts Yuu during Leviathan's approach

In Volume 1, shortly before 'White' Leviathan's assault on Midgard, Loki contacted Yuu by exploiting a weakness at the academy's defense system and requested for him to exterminate the D whose dragon mark had changed color, citing it as the most effective countermeasure. When faced with Yuu's reluctance, Loki subtly threatened him by stating that he would then have to take matters into his own hands, which might result in collateral damage. After hearing from Yuu that he would be the one acting as bodyguard for Iris Freyja, the girl whose dragon mark had changed color in response to Leviathan's approach, Loki promised not to interfere. However, it was implied that he goaded another NIFL leader to send a squad to kill Iris in order to back Yuu into a corner and ultimately have him take care of everything. Following Leviathan's defeat, Loki contacted Yuu and congratulated him for a splendid job, promising him to grant him a favor in the future as a reward for his services, as well as stating that he would count on him from now on for future occasions.

Scarlet InnocentEdit

In Volume 2, Loki contacted Yuu once again, through the proper channels this time, in order to warn him that the Sons of Muspell would make their move soon in order to recover Tear Lightning, stating that the leader of the cult, Kili Surtr Muspelheim would appear herself. While he stated that Kili was stronger than Yuu, Loki expressed his belief that Yuu could handle her, advising him to abandon his obstinacy of not killing people if he had things he wished to protect. He also subtly reassured him that NIFL would not make a move like they did in the Leviathan case before signing off.

Crimson CatastropheEdit

In Volume 3, during the operation against 'Red' Basilisk, Loki was contacted by Yuu, who requested his aid in securing Mistilteinn's prototype for the Dragon Subjugation Squad's operation against the Dragon as his reward for handling the Leviathan case. After asking Yuu if he really had things he wished to protect that much, Loki assured him that he would do his best, although he could not guarantee success. Eventually, Mistilteinn was handed over to Midgard, playing an important part in Basilisk's defeat.

Spirit HowlingEdit

Loki came into contact with Yuu once again in Volume 4 during the latter's visit to the Principality of Erlia. After congratulating him for defeating Basilisk, Loki commented that he was fortunate he didn't have to fight 'Yellow' Hraesvelgr, since that Dragon was regarded as impossible to fight. He then asked him to eliminate Kili, which Yuu refused on the grounds that Kili was under Midgard's protection. Loki wasn't bothered by this and asked him to simply not interfere with NIFL, but stated that if Yuu still chose to fight, it would be a great opportunity for him to become the complete Fafnir. After Hraesvelgr's defeat, Loki called Yuu to congratulate him for his achievement, brushing off Yuu's protest about having sent Hreidmar to kill Firill Crest. Loki proceeded to inform him that Kili had gone missing along with Jeanne Hortensia, asking Yuu to tell him if he found out any news about the latter. When Yuu asked him if he succeeded in making him the complete Fafnir, Loki's response was that he didn't, stating that something inside him was in the way. He continued by cryptically saying that perhaps the matter of being in the way went both ways before signing off.

Midgard's CarnivalEdit

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Loki meets the disguised Yuu in the school festival

Loki appeared before Yuu during Midgard's school festival in Volume 5, calling his female disguise a joy to behold. He then explained that he was part of NIFL's observing delegation and asked to speak with Yuu alone. After he was led to the school roof by Yuu, Loki attacked him and easily pinned him down, stating that he was an easy opponent without the intent to kill. When Yuu asked him of his purpose, Loki replied that he wished to discover what exactly was obstructing Fafnir from becoming complete. He continued by stating that Yuu currently had fewer gaps in his psyche and asked him if he had become a puppet of 'Gray'. Upon seeing Yuu's confusion, Loki theorized that the one who had filled his gaps was probably the one who had broken him in the first place. Addressing it, Loki declared that Yuu was his as long as Fafnir was inside him. However, Lisa Highwalker's appearance forced Loki to release Yuu, stating that he would have to wait for the next opportunity in order to draw out the mysterious existence that was obstructing Fafnir. When Lisa accused him of subjecting Yuu to violence, Loki replied that he was merely helping him train before leaving the scene.

Black NemesisEdit

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Loki contemplates using Yuu to deal with Kraken Zwei

In Volume 7, Loki was sent by NIFL to Asgard's First Laboratory in Tokyo in order to handle the aftermath of Kraken Zwei's escape. After introducing himself to Kenya Miyazawa, he announced his intent to exterminate Kraken Zwei by using Sleipnir or, in case they failed, Yuu. Following Sleipnir's failure to kill Zwei, Loki was contacted by Major General Dylan and persuaded him to seek Midgard's help, with the intent of using Yuu to deal with the newborn Dragon. Later on, he was approached by Director Miyazawa and informed him of the fact that Kraken Zwei was still alive despite the efforts of Sleipnir and Midgard's Ds. When Director Miyazawa started talking about the Fafnir Project and its relation to Yuu, Loki warned him about digging too deeply into this matter. He then informed him that Kraken Zwei had marked several Ds as her mates, including Kenya's daughter, Ren Miyazawa. Loki proceeded to declare that only two solutions existed, namely defeating Zwei or exterminating the Ds, and asked Kenya to contact Yuu if he was worried about his daughter and pass along the message 'You are the one making the choice' from him.

Amethyst Rebirth Edit

In Volume 8, Loki contacted Yuu through a speaker installed on Hreidmar's armor, expressing his joy that Yuu was able to easily defeat Hreidmar. He then proceeded to explain to Yuu that the Hreidmars were humans whose bodies had been altered as a result of obtaining a deviating power, likening them to Dragons in that regard. After calling them failed creations, Loki stated that Yuu was almost complete, having finally grasped the concept of killing intent. He then declared that he was bound by duty to protect mankind by eliminating the Ds whose dragon marks had changed color before signing off.

Cerulean Engage Edit

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Loki declares his intent to eliminate Charlotte

In Volume 9, Loki was shown to be en route to Midgard with a fleet of warships. After examining a status report about the deceased Dragons, he declared his intent to challenge Charlotte once more. The following day, Loki contacted Yuu, explaining to him how he had tampered with Midgardsormr to allow them to speak. He then revealed to Yuu that the world was sliding back into a state of war because of the elimination of Dragons, humanity's common foe, before asking him to eliminate Charlotte for the sake of mankind, calling her a monster who had committed grave sins. However, at that moment, Charlotte cut off the signal, interrupting his words.

In preparation for their invasion of Midgard, Loki visited Sleipnir, remarking that they were close to completion, and stated that they would acquire power on the level of Fafnir once the final member joined, before ordering them to move out in order to assassinate Charlotte. Afterwards, he had the Main Cannon Babel Replica destroy Midgardsormr's final defensive line and gave the troops the order to land.

Invisible Successor Edit

In Volume 10, Loki supervised the invasion of Midgard from the bridge of the battleship Naglfar, ordering the use of unmanned weapons to subdue the soldiers under Charlotte's control and having troops advance towards Midgard's core from the underground. Loki then declared that Charlotte's plan was foolish and that he had already killed them all. While Ariella was advancing towards Charlotte's location, Loki contacted her, assuring her that the deal she had made with Captain Shelley would be held and expressing his wish for her to be victorious. After Ariella cut off communications while calling him powerless, Loki inwardly agreed with her assessment while inspecting the Hreidmars, but stated that he never envied them, since he was able to avoid becoming a pawn of NIFL's leaders like his father. Afterwards, he declared his intent to abandon his powerlessness in order to complete the task of annihilating Charlotte, since both Yuu and Sleipnir couldn't respond to his expectations.

Major Loki, accompanied by two Hreidmars, proceeded to appear before Yuu and the members of Brynhildr Class, greeting Yuu and expressing his surprise that he was able to stop Sleipnir and Ariella without killing them. After explaining everything regarding 'Colorless' Fafnir, he then revealed to Yuu that he had not inherited his father's Authority after his death due to the fact that he had not been born at the time, and proceeded to explain the true nature of Charlotte's Authority, which was the power to unite mankind in a single being. When Yuu questioned him about the reason he had to kill Charlotte since she wouldn't allow her power to run out of control, Loki explained that her Authority was imposing peace on the world, thus ending human lives which could only be extended by fighting, while also expressing his desire to become a true hero by eliminating her. After that, Loki revealed to Yuu the mechanics behind Hreidmar's creation and how he had transferred parts of Code Lost to Yuu by killing holders of the scrapped factor with poison mixed with his blood. Following that, Loki also revealed that he had used the same process to inherit Code Lost himself from various holders, while having also inherited Sleipnir's factor due to the fact that they had ingested his father's blood to activate their own factors, calling it an unexpected occurrence. Loki then proceeded to exhibit Code Lost's power to interfere with the law of causality through thought alone, using it to kill the remaining Hreidmar in an indirect manner. Upon seeing that Yuu had his guard up, Loki asked him to relax, since his Code Lost was still incomplete and could kill neither him nor Charlotte. After Yuu yelled for the girls to run away, Loki called his actions pointless, since Code Lost did not have a concept of distance, and declared his intent to kill them, signaling the start of the battle between the two.

V10 I8

Loki is killed by Yuu

Due to the fact that Loki possessed a larger quantity of Code Lost than Yuu, he was able to easily evade his attacks by interfering with causality, stating that he had already imagined the manner of the girls' deaths. Despite Yuu's fierce assault, Loki still countered his attacks while also inflicting wounds on him. After announcing to Yuu that the girls had been killed, Loki was delighted to see Yuu attacking him in hatred before shooting him in the chest. While surveying Yuu's fallen form, Loki called this a disappointing ending, revealing that he had lied about the girls' deaths, but that his lie would become truth upon inheriting Yuu's factor. However, he was shocked when Yuu rose up covered in Hraesvelgr's Ether Wind and pierced him with his arm. With his final breath, Loki stated that he was satisfied with this result, since Yuu would inherit his part of Code Lost. As such, he would kill any human he knew due to his inability to control the fully activated Authority, stating that he would surely commit suicide after killing Charlotte and inheriting h
V10 I9

Loki after being healed by Kili

er Authority, which would result in it spreading around in a weakened form just like Code Lost. When Yuu asked him why he went that far, Loki answered that he merely wished to actualize the meaning of his birth, before seemingly dying. However, his injuries were healed by Kili's biogenic transmutation, reviving him. When Loki asked her if she did this to make Code Lost's transfer incomplete, he was surprised when Kili stated that she did it in order to prevent his death from weighing on Yuu's heart. Upon hearing that, Loki started laughing, finding it hilarious that he survived due to someone's self-centered reasons. Despite the fact that all his plans had ended in failure, he was satisfied that he had achieved his minimum objective, namely making the rulers of the world realize their folly in trying to exploit Charlotte’s Authority and stop demanding things from her. However, he delightedly stated that this accomplishment was still not enough for a hero before leaving.

Prismatic Garden Edit

V11 I10

Loki consults Atla about the identity of the unknown creature

In Volume 11, Loki was seen heading to NIFL's branch on the American west coast, where he was scheduled to stand trial for his invasion of Midgard, although it was a mere formality. However, he was notified by his subordinates that an unknown dome-shaped territory had devoured the branch office, with three such territories having appeared in other places around the world. When his subordinates displayed images from the destroyed branch office, Loki noted that a heart with several blood vessels around it had appeared on top of the dome, stating that it wouldn't be strange if a body was eventually created. After encouraging his subordinates, Loki seeked information from Atla about the nature of this creature. By using data salvaged from 'Green' Yggdrasil's remains, Atla informed Loki that the creature was the Fifth True Dragon, 'Eternal Longevity' Bahamut.

Darkness Disaster Edit

In Volume 12, after being informed of Bahamut's identity, Loki ordered a simultaneous attack with missiles from NIFL's bases around the world, asking Atla to coordinate them. However, the attack failed due to Bahamut's regenerative capabilities, with Atla stating that their firepower was insufficient to exterminate the True Dragon. When Bahamut took on the form of a giant dragon and began moving towards the unknown territory in the arctic, Loki immediately ordered his subordinates to set course for the Alaska branch to make preparations for intercepting the True Dragon, while also making contact with Charlotte to inform her of the current events.

Following Atla's capture by Tear during the former's attempt to sabotage Marduk, Loki contacted the Dragon Subjugation Squad, explaining Atla's origins as the AI that governed the civilization of Atlantis and the means by which NIFL had recreated her. After Yuu admitted that he couldn't control Marduk efficiently, Loki asked Atla to explain the way to operate Marduk, ignoring her suggestion to take over the battleship by stating that the key to this operation wasn't Marduk, but Iris Freyja's Catastrophe. He then suggested for Jeanne to become Yuu's co-pilot due to the fact that she was descended from Atlantean soldiers, thus enabling her to operate Atlantean weapons efficiently. Loki then began a discussion with Haruka over the details of the upcoming operation.

V12 I8

Loki states that he prefers fighting against Yuu

During the first operation against Bahamut, Loki commanded the NIFL forces from the battleship Naglfar, acting mainly as a diversion against Bahamut. Following the operation's failure, Loki informed the Dragon Subjugation Squad that a second defense line had been established in the waters of Norway, stating that it was imperative to stop Bahamut's advance there before it linked with the second unknown territory in Africa. Shortly before the battle's start, Loki conversed with Yuu, expressing his faith in Yuu's ability to perform the impossible. However, he was surprised when Yuu speculated that their survival during their confrontation back during Midgard's invasion was due to Atla hesitating to fire the Babel Replica. Loki stated that talking to Yuu was interesting before taking his leave, remarking that battling with him to the death was more preferable though. During the second operation, despite an unexpected intervention from 'Anomalous Dawn' Nyarlathotep, the united front of NIFL and Midgard successfully destroyed it and Bahamut thanks to Shion's Antimatter and Iris' Catastrophe.

Powers and AbilitiesEdit

Code Lost: Loki was able to inherit the scrapped Authority in Volume 10 by killing a hundred other successors with poison mixed with his blood in order to inherit their factors, and by absorbing Sleipnir's factor. Due to the fact that he is a descendant of 'Colorless' Fafnir, Loki's body did not exhibit signs of transforming into smoke like Hreidmar.

  • Fafnir: Loki's senses and physical abilities are also presumably augmented like the other holders of Code Lost.
  • Causality Manipulation: Because of the large number of inherited factors, Loki is able to exhibit power close to that of the original Code Lost, allowing him to twist causality to inflict certain death upon a person merely by imagining it. It also enables Loki to evade attacks or make his own unavoidable.

Hand-to-hand Combat: Loki has displayed a great proficiency in close-quarters combat, being able to immobilize Yuu with minimal effort.

Expert Tactician: Loki has exhibited great tactical skills, being able to formulate complex plans with multiple countermeasures for all possible outcomes.


Yuu MononobeEdit

Loki was Yuu's superior officer during his days as a NIFL soldier. Loki trained Yuu to be his most prominent assassin and has great trust in his abilities, always leaving it up to him to decide whether to kill his targets or not. According to Loki, he and Yuu are very much alike, which is why he is fond of him.

Charlotte B. LordEdit

Loki seems to despise Charlotte and is set on killing her, regarding her as the worst Dragon due to her influence over humanity. He believes that due to Charlotte dominating the world and imposing peace, those whose lives cannot be extended except by fighting will end up dead, thus making her extermination necessary in his eyes.


  • His name is derived from Loki, the Norse God of Mischief, while his surname is derived from Jotunheim, the home of the giants in Norse mythology.
  • He shares a great resemblance with Charlotte's father, the first 'Gray' Vampire. That is because he is a descendant of Leonardo's older twin brother, the first 'Colorless' Fafnir.