Was thinking back on it and the rich bitch is tarsh, but her family is worse, as they hypnotyzed MC into serving her and it was perfect mind control, only broken because she casually said the code words to release him for it.
They hypnotyzed a kid into becoming a slave, the rich girl is terrible but coming from that kind of family that spoiled her rotten is prrfectly understandble, is not that MC had a personality that wouldn't make him say "no", he was unable to even formulate the thought, mosnters.
And the bitch had a servant that did everything she wanted and a terrible uprising, of course she starts to treat him badly, as MC never refused she thought everything she did was fine, her love was real, but became corrupted.
Not trying to make excuses for her, but her family made her grow up broken as a person.