Takuma Miura is the former administrator of the Shoshidai, an organization dedicated to collecting and containing cursed weapons. Before his encounter with the demon sword Zsoltgewinn, Miura was a gifted musician, a capable and respected leader, and a devoted husband and father to his wife and daughter, Kyouka. His genuine love for his family and his sense of responsibility defined his early personality.

Miura's role in the story shifts dramatically after he becomes a wielder of the demon sword Zsoltgewinn. The weapon gradually consumes his humanity, transforming him into a Chrysalis and eventually into a Busoma, a monstrous entity driven by violent impulses. His appearance changes as he falls under the sword's influence, his hair turning white and his attire shifting to a dark suit and coat. Despite his transformation, fragments of his former self remain, evident in his daughter's desperate plea to the Shoshidai to use a prototype vaccine to save him rather than destroy him. This creates a tragic dynamic where Miura is both a formidable antagonist and a man whose identity is being erased by the very weapon he once sought to control.

As a Busoma of Zsoltgewinn, Miura possesses immense demonic power, making him a significant threat to the Shoshidai and the other Chrysalises. His abilities force the organization to deploy its strongest warriors, including Seiya Ichijo and Gai, in direct combat against him. The battles against Miura's Busoma form culminate in a confrontation where the Shoshidai attempts to end his rampage, while Kyouka holds out hope for a cure. Miura's character development is defined by his descent from a respected leader into a tragic monster, highlighting the central theme of the series about the loss of humanity to cursed weapons.