The Magic Stolen From Him by Skylar A. Blevins

In a world closer than she knows, Liara Norrison finds herself in an unlikely situation. On the day of her twenty-first birthday, she learns that she is not what she seems, nor will her life ever be the same. Not only is Liara the mate of the Tri-brid King, Reznor Nighterious, who has been known to make more enemies than friends, but she is also the last Nightlighter to ever be created.
As she travels with Reznor to the court of Dwimmer where he and his people live, Liara finds herself meeting people and creatures she never knew existed. She was destined to be his queen before she was even born, but will it help her make her final decision? Despite falling in love with the lands and starting to gain an understanding of the man who rules them all, Liara finds herself with a new problem.
A creature determined on stealing Reznor’s powers begins to wreak havoc across his world and his lands. The pair must work together to save his home and everyone that resides in Nightsend. A task that will not be easy for Liara or Reznor.
Their fates are intertwined by the gods, a written prophecy that has been around for thousands of years. Only Liara and Reznor can decide what path they take in their future.