The Greek God of Sleep, Hypnos, as an SMT Demon.

Gave them long flowing hair for appeal.

Their crown is bronze, with a swirly, circular jewel. a circular swirl is a common symbol of hypnosis, named for Hypnos himself.

Their eyes are closed because he is the God of Sleep.

The cloud/bubble shoulder pads were inspired by bubbles and clouds being symbols of sleep in anime and in general respectively.

The throne has Greek pillar armrests, and a nebula within that spills out of the bottom. A nebula is visible in the night sky (without light pollution interfering).