
My theory is that the dad probably obsessed with her because she look like his dead wife or something, not actually seeing her as human being or a person as her own and because he scared to lose her again he keep her locked up. Her being bitter about it and unable to do anything about it took her anger out on ML- being the son of the two people who ruined her life. ML probably felt responsible as a child and that why he endured it. That’s what I think at least

Based on the most recent chapter, the dad only had the stand in wife as a means to prevent other forms learning about his true love. Might be due to knowing that his enemies would harm her in order to get to him. After she died, the duke likely fell into an urscapable depression or maybe even somehow being manipulated by the stand in. I mean, he did lash out really bad the moment his true love died and told her she would never be real. The stand in probably has an inferiority complex as well as hatred towards the duke for not choosing her which led to her tormenting ML.
So the ml biological mother isn’t the current one that abused him? I thought she did that because she didn’t like his possessive bloodline but now everything she’s doing and how possessive the father is about her is confusing