Don't think this is translated into English but I will give a rough summary of the plot. The MC who got turned into a woman by an artifact that the steward (Man with long hair and monocle) called Carlo identifies since that is his ability. He is sick of the MC who is the chosen hero to fight in this war between other chosen heroes neglecting their duties. Tricked the MC into wearing the genderswap ring that lowered the MC's level as well. Then he forced a slave collar on the MC while their guard is down. Basically Carlo wants to make the MC part of their noble house so they no longer have to worry about money while he gets a wife who he can easily convince to go to war to do their duty they have been neglecting to make money.
What is really messed up about Carlo is that they raped the MC who was a slave that couldn't disobey their orders until they were mind broken and accepted they were a woman. Then what makes Carlo more even worse than more villains in hentai is after mind breaking them proceeds to on page 28 wipe their memories of everything that happened while the collar was worn. So even though they already made them submit the MC now wakes up in bed as a woman confused saying they are a man and Carlo gaslights them by saying your my fiance and have always been a woman. Then proceeds to prove it because the MC reacts to Carlo's touches based on muscle memory so believes that Carlo must be right otherwise their body wouldn't react to him this way.
So Carlo basically mind broke the MC only to wipe their memories of all the rape only to mind break them again.