Witch King's Oath - Heirs to Eternity, #1

Spellbinding and unexpected, Witch King's Oath is a bold-hearted fantasy adventure packed with magic and intrigue, perfect for fans of Samantha Shannon and T. Kingfisher.  Magic and politics collide when Prince Anryn of Ammar survives an assassin's blade at a witch trial gone wrong. On the run and desperate for help, he turns Maertyn Blackfire, a lonely witch cursed with immortality by the mages of Nynomath, Ammar's enemy.
An unlikely friendship forms over the promise of whiskey and not too many questions asked while Maertyn escorts Anryn home to his witch-murdering father.  When a brush with Maertyn's past awakens Anryn as a witch under a curse that hides a woman's soul beneath Anryn's skin, the prince is forced to question everything. including who her enemies truly are.