Cruel Beauty is a Beauty and the Beast retelling with Greek mythology mixed in. That right there was enough to sell the book to me.
Nyx has known since she was a child that she must marry the demon, Ignifex, who ruled her kingdom because of a deal that her father made with that demon before she was even born. And because of that, Nyx has been training to kill her husband-to-be, all the while cursing her family for her fate. To find a way to save her kingdom, Nyx must learn all of Ignifex's secrets, but doing so isn't easy, especially when she finds herself starting to fall for him.
What I really liked about this book was the fact that none of the characters were really good. They all had some evil in them, in one way or another, and it made for complicated relationships between everyone. Nyx is filled with conflicted feelings, and it's really easy to see why when you consider how she was raised. And I loved having a love interest who is not good and who the story does not try to portray as good. Everyone is capable of cruelty, and that is acknowledged throughout the story, which I loved.
I will say that the ending is a bit...strange and a little confusing. Even after thinking about it a bit, I'm still torn on whether I truly liked it or not. My favorite part of the story was definitely the middle, particularly whenever Nyx and Ignifex interacted with one another. But that's largely because I love antagonistic relationships. And Cruel Beauty certainly delivered on that.