Enmu

Blood Demon Art: Sleep Manipulation

As Lower Moon One, Enmu's Blood Demon Art puts victims into deep sleep and lets him manipulate their dreams and fabricate false realities, which he used to trap the entire Mugen Train's passengers and crew. When defeated, he awakens a final, grotesque form by fusing his body with the train itself, becoming a massive fleshy mass of eyes and mouths before Tanjiro destroys him.

Enmu has a pale, ghost-white face bisected by a single stitched line, wild teal hair, and an ever-present unsettling smile. His demon form can meld into wood and flesh, sprouting eyes and mouths across any surface he infests.

Enmu is gleefully sadistic and finds cruelty entertaining for its own sake, toying with his victims' dreams before killing them. He shows open contempt for humans, though he turns cowardly and panicked when truly outmatched.