the thing is, people who read story with rape means that they dont have any problem with rape being in the story. that includes morally-wrong character and unforgivable wrongdoings. so if rape is out of question here, i personally sympathize with seo in because he clearly has a solid backstory that led up to his current moral and personality, not all rapist are people with sexual harassment trauma, that explains why seo in behave like that: because he wanted to live as his step brother (i forgot his name) that had exploited him his whole life and he is doing so just to make himself feel better. so does that mean he is a very self centered prick? well hell yeah. but moral is out of the question in story like these
"not all rapist are people with sexual harassment trauma, that explains why seo in behave like that", that's my point, Seo in would turn into a rapist no matter what he went through, he is no victim.
What makes for readers some rapists better than others? Seo in is a rapist, no trauma with his family can justify that. POTN or niichan show what can turn an innocent child into a rapist, and it's still not enough justification. This here is a child that was abused by his family and it's completely unrelated to becoming a rapist. No, he is not a victim when it comes to Yeongwoon, his trauma has nothing to do with sexual assault, it's like saying I was bullied in school so I turned into a rapist, does that make any sense to you?
The only victim here is Yeongwoon, Seo in is a rapist, Yeongwoon never did anything to deserve all he went through and never harmed anyone, how can people put them both on the same level? A victim of family abuse that sexually assaulted the one he claims to "love" will never be the same as the victim of assault that went through hell his whole life but never assaulted anyone. And to see Seo in is the one that readers sympathize with the most... It's kinda sad.