Responses
I read some SPOILERS somewhere and it said:
that he likes seeing her show her emotions, cuz he too , since he was young was faking like Roxanna but lost himself along the way, he doesn't feel anything anymore, so he obsesses over our FL cuz she didn't go crazy like him and can still feel and show her emotions so he likes to see her angry or sad especially when it's directed at him , it excites him not like sexually but mentally i guess ? but yeah he is obsessed with her however not romantically
So is the badass brother, the one who killed the twin, in love with her too?