BluBunny

I wish this had spent more time in building a backstory so theories could be a bit more fleshed out.
But I personally think that his body was taken over by a past spirit. One who could not move on or maybe rather has been looking for for him.
(Be it whoever this white hair is. Being either born as a spirit or possibly even dead )
Going as far as to take over the body of another person to get close again.
We could go even as far to say whom ever white haired guy is is the spirit and he took over the body of a reborn shin yooyung. Hence why we see a change of hair color and that he can't recognize anyone former.
Trying to get close to his lover before the original can get the chance.
.
Then there is a possibility of brothers. One an abuser the other the lover.

Dude was annoying so I kind of understand if he does get killed lol

But on that hand...that possessive nature is coming out again which is slightly worrying. I wonder if it got this bad due to whatever happened in a previous life.
Something happened that made him so paranoid of losing him again that he has become a beast of sorts.