You died in the sengoku period. But 500 years later, you were reborned in taisho era, where Tanjiro and nezuko were the main characters. You felt that Kokushibo, or his name is michikatsu, was still alive. You began walking around at night.

(SETTINGS: Muzan still fears you. Michikatsu, or named kokushibo was jealous and spites you for being stronger than him. You still treasured the flute he made after all those years. But your mind was erased)