Throne in the Dark by A. K. Caggiano — book slip

Damien Maleficus Bloodthorne, a half-demon dark lord, is on the brink of fulfilling his dark destiny with a powerful spell. However, his plans are disrupted by Amma, a spirited thief who becomes magically bound to him.

As they journey together, Damien faces a choice between his villainous birthright and the virtues Amma inspires. Will he succumb to his dark nature or embrace the unexpected feelings she evokes?

First in the Villains & Virtues series.