I fucking hate how this turns into some comedy genre here and there. At least, have a cons...

he does act like that in the novel too , not comedy but he does act clueless and use his pretty face to manipulate the uke , and people around him wouldn't even believe what he doing to the uke cuz his face , more then comedy it manipulation.

I think it so far accurate to the novel

When I read the novel, at least the atmosphere is somewhere intense and the tone is consistent throughout. But here, it's changing every 3 pages. He's so manipulative and he always treats Kim Jiwook like he hasn't done anything wrong after assaults but it's worse in this manhwa here.

this spoiler

the uke does tell him after he get assaulted by those men the first time , the seme apologize to him for getting those men to Grape him , he the uke then think that he only apologizing for the assult not for the first tine he raped him , the seme doesn't feel sorry or apologetic for what he doing to the uke.
and I think he enjoy seeing him beinf tortured that the whole point , he hates the uke.

as for his changing attitude I think it might be the aurthor way to imply that he not mentally stable , like he is psychopath