Enmu was once a man who originally claimed to be a doctor, having caused several murders. He was never able to tell the difference between dreams nor reality. He's now a demon, becoming Lowermoon 1 of the Twelve Kizuki. He's a psychopath and can't feel any pain at all, considering when he was still a human; a demon (the Demon King himself, actually) was consuming his intestines and he praised said Demon King. After passing, the Demon King: Muzan Kubutsuji, was intrigued and turned him into one.