I think he developed a codependent disorder towards his hyung and so probably when he left things went to shit alongside his mental health.
In the first season he acted as oif he had a right to his hyungs body and presence bc hes the empereor so the power worsened his behaviour
Because nobody growing up in that environment under that kind of abuse will develop healthy coping mechanisms or emotional intelligence. He’s broken. Broken people don’t make good decisions. Asking of him to be a decent person as an adult with ZERO support system is farfetched and ridiculous. In fact, him being an obsessive, cruel and tyrant king who obsesses over the one person who ever recognized him as a human being makes perfect sense. He has no understanding of normal and healthy love. He doesn’t know it.
All of that. I try to explain all the time that this case is different.
ppl with excessive/obsessive feelings like our ML would rather you hate them than feel nothing for them at all. sam-myeong having hatred means he'll never forget.
So i really feel sorry for him Abt what happened but i still don’t understand why he couldnt just kill his Brothers/father and leave Sam-myeong alone and slowly After his wife died making him Fall in love with him. Sam-myeong Was the only one who treated him right so why even crush him to the point he HATES him than love him… it didn’t have to be toxic so they could be together.