I mean.. ok he is gentle but he's also a merciless killer that could kill her at anytime. for me his actions are not based on love or feelings for her, is more like I need you to live because you're a pacifier and that's what's throwing me off
like the previous comment said, maybe on the novel is better but their relationship is kind of meh for me,,, ╮( ̄▽ ̄)╭
She knows from her heart that he is pretending. Yes, maybe he will fall for her later, but at least for now he is wearing a mask and acts like he loves her to lure her in; and she's well aware of it too. She admits it herself lol. And you said he makes her happy and protects her siblings, but is it part of his responsibility since he agrees on the contract they have.

Idk, maybe the novel describes their relationship better? The way their relationship develops is so weird to me, like it doesn't make any sense at all. I don't find any reasons for her to fall for that type of guy, especially when she knows how delusional and crazy he is...