OVA
Description
M-21 is a modified human created through the Union’s experiments under Dr. Crombel. He was one of the first one hundred human subjects and was designated as the twenty-first in that batch. Originally classified as a failed experiment, he retained no memories of his life before the procedures. He was given the lowest-ranking agent position within the Union alongside M-24. His body was subjected to extensive genetic modification, and he was implanted with the heart of a werewolf, a species nearly as powerful as the Nobles but far more obscure. This unique modification set him apart from other M-series subjects.

In his early appearances, M-21 displayed a cold, rebellious personality. He often sought out trouble and conflict simply to relieve his boredom, and he carried himself with a defiant attitude. He had begun developing the ability to transform his physical shape, which he kept hidden from the Union, knowing they would continue experimenting on him if they discovered it. His motivation initially centered on discovering his lost identity and that of the other test subjects, a goal he shared with his closest companion, M-24. After M-24 was killed while defending Shinwoo and his friends, M-21 was profoundly affected. He moved in with Frankenstein and Rai, and Rai helped him glimpse his true latent powers, urging him not to underestimate their origin.

M-21’s role in the story evolves from a conflicted former Union agent to a dedicated protector. He becomes a special security officer at Ye Ran High School, the institution run by Frankenstein, and joins the group known as RK. His primary objective shifts from uncovering his past to safeguarding Shinwoo and the others from the Union’s threats. Later, with the help of Tao, he learns that the data regarding the test subjects’ identities had been recently destroyed and that his defection was never reported, intensifying his sense of urgency.

Key relationships include his bond with M-24, whose death serves as a turning point that pushes M-21 toward a more selfless path. Frankenstein acts as a mentor figure, guiding M-21 in understanding and controlling his abilities. Rai is responsible for awakening his powers and remains a figure of trust and authority. M-21 also develops protective ties with Shinwoo and the rest of the group, gradually integrating into a makeshift family.

Developmentally, M-21 starts as a reckless individual driven by personal loss and a need for answers. Over time, he makes peace with M-24’s death and abandons his quest for his original identity in favor of protecting his new allies. This transformation is marked by his decision to prioritize the safety of others over his own desires.

M-21’s notable abilities stem from his werewolf heart and extensive modifications. He possesses the power of metamorphosis, allowing him to alter his physical form, a skill he initially keeps secret. He exhibits enhanced strength, speed, and regenerative capabilities. His combat style combines close-quarters fighting with strategic evasion and tactical thinking. Under Rai’s awakening, he briefly experiences a full transformation and learns to access deeper layers of his power. Over the course of the story, he approaches a full awakening, putting his fighting strength on par with or slightly above that of Regis after Regis acquires a soul weapon. His abilities are not without limits; overexertion can cause both physical and emotional strain.
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