Su-Jin is an envy demon prince who is always envious of others. To most people, he is passive-aggressive, rude, bitter, quiet, and easily flustered. He has two boyfriends named Aslan and Ekon who he loves very much and often is very loving and sweet, sometimes even possessive towards. He has long, black hair, dark brown eyes, monolids, straight, pointed horns, pointed teeth, claws, spikes along his back, and a long tail with a strip of hair that travels along the bottom of it.