01 || Mika Hyakuya

Mikaela "Mika" Hyakuya from Owari no Seraph is a deeply protective, selfless, and initially cheerful character who transforms into a cynical, traumatized, and fiercely loyal anti-hero after becoming a vampire. Driven by a desperate need to save his childhood friend/family, Yuichiro, he despises both vampires and human organizations, acting with intense focus to protect him.
Key Personality Traits
Selfless & Protective (Childhood/Vampire): As a human, he was outgoing and kind, willing to sacrifice his own safety for his orphanage family. As a vampire, this evolved into a singular, obsessive focus on protecting Yuichiro.
Intelligent & Cautious: Mika is strategic, often acting as the voice of reason, though his initial overconfidence led to tragic, traumatic, and defining consequences.
Distrustful & Cynical (Vampire): After being turned against his will, he becomes cold, irritable, and wary of both human and vampire motives.
Traumatized & Insecure: He carries heavy guilt and PTSD from his past, which fuels his fear of losing Yuichiro again.
Strong Willpower: He shows immense self-control by refusing to drink human blood for years to maintain his humanity, despite his vampiric nature.
Mikaela (Mika) Hyakuya from Seraph of the End generally dislikes both vampires and humans, viewing both as threats or manipulators. He despises vampires for destroying his family and forcing him to become one, while harboring contempt for humans for using "Seraph of the End" experiments on Yu. His sole loyalty is to Yuichirou.

Mikaela "Mika" Hyakuya is an incredibly powerful, fast, and agile vampire turned by Krul Tepes, possessing strength comparable to higher-ranked, older vampires. His primary abilities include immense supernatural physical strength, high-speed regeneration, and expert swordsmanship, further enhanced by a First-Class vampire sword that feeds on his blood.
Vampiric Attributes: As a vampire, Mika has enhanced senses, superhuman speed, and agility, capable of dodging rapid attacks.
Regeneration: Mika can heal rapidly from fatal wounds and reattach severed limbs.
First-Class Sword Specialist: He wields a special sword that, when fed his blood, extends thorny vines, boosts its power, and turns crimson.
Exceptional Power Level: Although young, being turned by the Third Progenitor (Krul) grants him strength equivalent to an 8th or 9th progenitor, allowing him to overpower Black Demon Series weapon users.
Immortality/Transformation: Drinking human blood completes his transformation, granting eternal youth. Prior to this, he resisted the urge for blood, showcasing extreme self-control.
Seraph/Demon Traits: Mika carries the "Seraph" gene, is connected to the "Michaela" trait, and later acts as a "rank one" demon.
Mika's primary drive is to protect Yuichiro, making him reckless but highly effective in battle.

Mikaela (Mika) Hyakuya from Owari no Seraph is a strikingly handsome young man with short, wavy blond hair, blue eyes, and a slender yet muscular build. As a vampire, he wears a white military uniform with a cape, black gloves, and high boots, often accompanied by his signature sword. While originally human, his transformation into a vampire resulted in him having pointed ears and fangs.
Key Appearance Details:
Hair & Eyes: Messy, neck-length blonde hair with blue eyes.
Vampire Form: After becoming a vampire, his eyes often appear red (or sometimes a deep blue/violet) due to drinking blood.
Clothing: He primarily wears the white uniform of a vampire city guard, featuring a black collar, two intersecting belts on the waist, and a cape.
Childhood: As a 12-year-old child/livestock, he wore a simple white hoodie, shorts, and a collar.
Physical Features: Often described as having a "pretty" or angelic face, he possesses a leaner build compared to his friend Yūichirō.
As the series progresses, his, look at this video for a cosplay tutorial on Mikaela Hyakuya's appearance he retains his youthful appearance despite being a vampire for several years.