I was going to draw his fox form to go with this,but I've decided I want to draw humans in a more realistic way for a bit. This'll be the last reference I put up for a while.
Ji Yeou is a fox spirit, capable of manipulating illusions and hallucinations. His powers are much stronger in the light of the moon. He's a pacifist, or rather, attempts to be one. His murderous urges are calmed as long as he looks at the full moon every month.
His fox form is simply a fox with three tails.
Ji Yeou is mostly based off Korean myths, rather then Japanese or Chinese. I find the Korean model much more interesting.
(That version of the song is amazing. I usually don't like it at all.)