Is this guy perfectly fine with "Dad" being a... Loli?
How? Why? What?
Also, we're again dealing with that chestnut of 'threaten the love to make the target submit'. Has that plan ever actually worked on anyone outside of a minor character for plot advancement?
I don't think it ever has, if anyone knows of a time it has worked, let me know.
You'd think for an Assassin, assuming head of the family, he'd take into account the thought of revenge. And considering the personality and the obvious sadist nature (what with the 'example' of her former pet hamster), he'd likely continue to push the boyfriend's death on her, which only adds fuel to the fire.
TLR, I hate this trope because it doesn't fundamentally work in a literary scenario.