I agree with you that he's an usalvageable asshole. But I think it's really a shame it wasn't shown properly here in the webtoon. I read a bit further in the novel, he had been actually admitted to a mental hospital in the states before and the doctors diagnosed him with that disorder. The problem though was that his parents didn't want that diagnose officially to be put in the documents since it would ruin the reputation of their family. So to avoid that altogether they send him to korea. I actually don't remember everything very accurately, since it's been a while that I read the novel, but I think when wooyeon arrived in korea he actually ran away and became an actor at the first agency he saw there in order to get away from his family. I could be wrong tho, since it's really been a while. The bottom line is, he's very aware that he's a bitch, but I don't know if he's really trying to manipulate the mc with his confession. He is a psychopath, but I don't think that his intention was to be forgiven. Sorry I am rambling, I'm just really not sure how to feel about wooyeon. That guy does piss me off though. I personally wouldn't want to involve myself with him.
I do feel like though, that he's showing his real feelings properly for the first time. He's shown faces I could never have imagined him to make
You know you ain't normal , you know you're ill and you need serious intervention but you still didn't seek help and just used your illness as an excuse for being the biggest a hole in the plant and even you're manipulating him into forgiving you while you said you're an award winning actor .. oh he's just the worst