There is a hentai with this same plot, MC is from a rich family, her family hates him and his sister wants him dead but can't outright kill him, but wants to do, and their mother wants it.
Womens have stronger powers and the MC had a pretty weak ability, then he discovered that by fuckign a woman and cumming inside he was able to copy their skills, he had a limit but done a girl with a clone ability and therefore remove dthe cap, to add to it any woman he had copied the power was unable to affect him with their.
This must be the same writer of that hentai, is too similar.
In that hentai the father was a powerful man that died, can't remember how, and the mother absorbed his connections and pushed for a world where man were ina weaker position, not because of something happening earlier, she just hates males.
If I'm right the sister there had a power creating a absolute barrier around herself, very different.
In this it makes a bit more sense that the mother hates the son of someone that cheated on her, less that MC decides to continue living with them, just run away and denounce how they want to kill you.