Ok, I will be honest and upfront, I DON'T like Rudy. He's still just a selfish perverted old man in the body of a young man, that the women in his life put up with his nonsense can only be explained one way, they want his power for their children. Sylphiette is a doormat, Roxy is impressed by his power and has confidence issues, and Eris is just stupid.
I think what really ruined him for me was when he just stood there and watched as a young beastgirl was raped and beaten to death in from of him. He was not helpless or powerless, he just decided her life wasn't worth his time. Compare that to how Ruijerd and Eris react when a child is in danger, they burst into violent action. His attitude towards slavery also pisses me off but that's another topic.
If the other people in the LN weren't interesting (Eris and Roxy), I wouldn't read it at all.