I don’t really understand their relationship with each other. What I do understand is th...

i’m pretty sure he’s is

Yes, but she is actually not his sister and he is kind of aware that it is not even her soul anymore.
That doesn't make it better, though...

Yes he's supper obssessed with her but also enjoys hurting her like man cannot make up his mind fr

Pretty sure your confusion will be cleared up in the next couple of chapters ╥﹏╥