His initial characterisation seemed to veer into that typical harsh ML that abuses the MC throughout the story. (I am glad he was quickly proven not to be, though)
The same can't be said about Joo. Like you said, his anger and violence is extremely realistic, and makes it very uncomfortable to read about. I don't want him to end up with Dan, but we all know he will. Smh
He has a total disregard to Dan's feelings, and gets off on his suffering.
But getting back to Kwon, I do hope he can put his pride aside, and own up for his mistakes and communicate rationally with Yeon-oh. I do wish them a happy healthy relationship as well. Especially when you see some manhwa brush things like that aside, and there's always this lack of closure, no apologies, etc