Both leads are twisted here

In this masterpiece we have two male leads that are very ambiguous and twisted. They are toxic to each other, yet those venomous snakes really suit each other and heal each other.

Here we have a Villainess that wants revenge because she was betrayed by the man who she loved and helped to become emperor. The male lead needs her help to his revenge. Both are kinda crazy, he's the evil brain and she's his sword basically.