Ginsei

ぎんせい

A mysterious creature wearing an eyepatch who shares a history with Ioryogi, though he now appears to be on poor terms with him and often challenges him to fights. Ginsei has also frequently stated that Ioryogi's current form is not his true form and seems to be aware of Kobato's mission. He does not think highly of Kobato or of Ioryogi's relationship with her. It is implied that he wants Ioryogi to return to 'Heaven' for unknown reasons, as it was Ioryogi who took Ginsei in and trained him. In fact, it has been mentioned that Ioryogi was the one who gave Ginsei his name. Ginsei's appearance, like Ioryogi's, is implied to not be his actual form, as when he stands atop a building overlooking Ioryogi and Kobato's apartment, his shadow is that of a young man with short hair.
Ginsei means "silver life" in Japanese, and Ioryogi gave him this name because Ginsei's eyes are silver.