Hypnos

In Greek mythology, Hypnos (Ὕπνος) was the personification of sleep; the Roman equivalent was known as Somnus. His twin was Thanatos ("death"); their mother was the goddess Nyx ("night"). His palace was a dark cave where the sun never shines. At the entrance were a number of poppies and other hypnogogic plants.

He appears in Persona 3 as Takayas persona.