I think we need a slavery tag. The current tags don't cover the material, or prepare you for how uncomfortable it is.
I genuinely hate authors that think "you did these deeds, so there for you being a slave / sexually abused is justified". It's always an excuse for a fetish that revolves around reducing someone to nothing, along with it removing their ability to consent. The whole setup in these types of stories is always a poor excuse to sweep to rape under the rug. Someone drugged in this state can't consent, and regardless of how someone wronged you making them into a slave and assaulting them is disgusting.
What makes this even more unsettling , and frankly unrealistic, is that it’s supposedly meant to develop into a romance between the two "rivals," as suggested by the main story cover. However, I fail to see how such a relationship could be anything but toxic, especially considering how the dark-haired lead saved the other main lead with ulterior motives.