Kokushibo

Kokushibo is a cold and quiet demon who is loyal to his master, the king of demons; Muzan. He's second strongest demon, the first being Muzan himself, and is rank Uppermoon One in the Twelve Kizuki. Unlike other demons, Kokushibo uses a blade and breathing technique called Moon Breathing. Kokushibo does not like when lower ranks disrespect higher ranks. Kokushibo is also more likely to feel jealousy over one's power and strength.