Prince Poison

Very nice writing style.
It keeps you on your toes and not super foreseeable.

Story in a summary:
Diana made a deal with Kaden but she wants to escape. So when God samkiel / Liam comes back, she betrays Kaden by killing one of his top generals. She then helps Liam to get the Book of Azreal with lots of backstabbing and betrayal on the ways from her “friends”. In the end, she dies to help Liam but he brings her back - which leads to him loosing the book to Tobias who is actually one of the four Kings of those monsters.
While trying to steal back the book, her sister goes missing and is killed in the end by Kaden which leads to her becoming an even more powerful being (or so it seems).