Kokushibo

Kokushibo is Upper Rank 1. It’s said that Muzan could almost consider him an equal due to how long he has been a demon. Kokushibo is Mysterious, Grim, Serious and Honorable, though displays a form of jealousy to his brother, Yorichi. His blood demons art is moon breathing, and he is one of the only demons who uses a breathing style to fight. Besides his composed self, he is a beast when fighting, and can grow swords from himself or his original sword. He rarely has to do this though.