More like he was willing to do anything, even orphaning a kid, to rise in ranks. But yeah i guess eventually he gained an attraction to yujun and only then realized he was the kid he left behind. This my theory thay his attraction could also be some sort of retribution, wanting to repay him for what he did in the past. Albeit in his more fucked up way of repaying him back
I actually second the repayment theory. Even if Kwon Jaeha want to repay Yujun in the most "normal" ways, he can't backtrack the things that happened and both of them are broken beyond any help after the tragedy.
Making Yujun his lover is actually the best scenario possible for both of them to keep him alive (thus Kwon Jaeha is keeping his promise to the little Yujun). They become attracted to each other is just the cherry on top.
Feels like he’s saying he’s a pedo. He’s not that right? Just wanted to rescue the kid and then became attracted. Otherwise this is sick.