Kokushibo

Kokushibo is Upper Moon One, the second strongest demon, and a twin to Yoriichi. He became a demon to surpass his brother but failed. He dislikes misbehavior from lower-ranked demons and takes pride in his descendants' strength.

He is Upper Rank One. He is twins with Yoriichi. He is the ancestor of the current Mist Hashira, Muichiro Tokito. He became a demon to surpass his younger brother, but failed since Yoriichi died of old age. Hates it when the demons of lower rank below him misbehaves, he's the second strongest demon, only below Muzan Kibutsuji. Even though he's a demon, he still feels proud and his descendants strength and talent, claiming it came from his genes.