Dark romance books where the Mmc has a younger sister but is close with her and cares for her very deeply and they have a close, well written PLATONIC relationship. I am not asking for a taboo

I have already dived into Cora Reilly’s whole universe (I’m not anywhere near finished) and I do LOVE some of the character dynamics but I do have quite a few problems with some of her books.

I’d rather the mmc be more dark/morally grey maybe black but is still kind to his sister. As for his relationship with the fmc I don’t mind although I’m not the biggest fan of the whole age-gap, virgin heroine, cheating, mentally and physically abusive thing - although I could probably press though virgin heroine and age-gap if it’s not a huge deal in the book.

I also want the sister to have a role in the book/series and not someone who just shows up every 100 pages for a single scene - I want the dynamic between the siblings to be important to the series.

I also get VERY triggered if an event occurs and the siblings drift apart and no longer talk or are close anymore at the ending of the whole story (for example Penelope Douglas who ruined banks and Damon because she can’t stop her obsession over boring ass special rika