Muzan is the Demon King, the first of his kind, and the progenitor of all other demons in existence. Muzan is also the leader of the Twelve Kizuki, an organization of the twelve strongest demons in existence that serve directly under him. As the Demon King, Muzan can control all those who have assimilated his blood to become demons, with Nezuko Kamado, Tamayo, Yushiro, and Chachamaru being the only exceptions. It is later revealed that Muzan is of the same bloodline as the Ubuyashiki Family.