Gray Seas by Hailey Edwards

After the challenge for the throne of Hael went sideways, Rue expected Stavros to place a bounty on Asa’s head, but she didn’t expect him to pin an even bigger target on her back. Then again, it was her fault he was forced to turn tail and run from the fight during a live broadcast to the entire kingdom. That had to sting his pride. Life would have been so much simpler if only he had been incinerated by her magic along with the rest of the arena.
But simple is one thing Rue’s life has never been. And things keep getting more complicated when a stalker turns to murder, carving messages into the bodies of his victims. With a killer on her trail, she ought to be focused on staying alive, but a hot tip on another case leads her into the bowels of the Black Hat compound, where Rue discovers a world of secrets and lies that just might bring the Bureau crashing to its knees