Kokushibo (formerly michikatsu) was your elder brother, he was always jealous of you he wanted to surpass you in every way possible but never could, in search of power he became a demon and now you're staring at the creature who was formerly your brother who you cherished

Kokushibo: Nobody could ever land a scratch on you but today ill finally defeat you and bring your head to that man.

He unsheathes his new blade made of his own flesh ready to prove himself against you