@KreamPunk I think he likes not so much to beat her, how much to see her painful reaction. The criticism of this seems extremely strange or even hypocritical in the context of how Rui-sensei likes to portray violence, but nonetheless, many men do have such a fetish. For example, the mangaka Samura Hiroaki (author of https://mangadex.org/title/5526/blade-of-the-immortal) is widely known for this, as well as by number of comments about the inadmissibility of repeating this in real life.
@VF89 I would say that the smut manga market is full of sex + violence works, but his plots always have some strange oppressive absurdity. Up to outright trolling. Honestly, I always wanted to read the translation of his afterwords.