Magic Waking by Eva Chase

Die, reincarnate, repeat. It’s been a long fifteen hundred years…

After centuries of deaths and rebirths, wizard Emma Hale—formerly known as Merlin—wants nothing more than to find the present incarnation of King Arthur and break the spell binding their souls in this morbid cycle.

Too bad she has no idea how she cast that spell in the first place. Oh, and she’s also got to fend off the shadow creatures aiming to kill Arthur all over again. Which might be easier if Arthur’s current host wasn’t so cocky yet distractingly good-looking that Emma is falling even harder for the man she can’t have.

When a fae mercenary with power to rival Emma’s puts her king in his sights, Emma burns through all her tricks just to stay one step ahead. No human she’s ever known has managed to kill a fae. But if she can’t, and quickly, this death might be their last.