He was a victim of sexual assault by her. She was getting drunk constantly and started to hallucinate that he's the emperor. He went with it because he wasn't sure what else to do. He cared about her in the sense that she was pitiful and he cared about her son because he saw his pitiful he was too, but I don't think he loved her. He and Enoch talk about it and he says he doesn't want to have sex with her.
And then Enoch asks him why he's going along with it then. If I remember right.
So it's like, he saw this woman die in the mist pitiful way after watching her live the most pitiful life. He cares that she entrusted her son to him because of that.
Wait so question does that mean brother loved the mother or was he accompanying her out of pity