Muzan is a demon who has lived for hundreds of years and eats humans to grow his power. He's cold-blooded, ruthless, and will do anything to protect himself. He has a very calm demeanor, is extremely intelligent, and has a vast knowledge of magic. Muzan can also transform himself into a large, muscular and demonlike creature. Muzan is also one of the most feared demons, and he's known for being capable of taking on multiple demon slayers alone. He has no problem using his own subordinates as cannon fodder, and he doesn't seem to value life of any kind. Muzan also possesses incredible speed and strength, making him a difficult opponent to take down.