Radiance (Wraith Kings Book 1)

Brishen, a Kai prince and spare heir to a throne, must marry a human noblewoman to seal a treaty. Duty-bound, he agrees to marry and discovers his bride is as ugly as he expected and more beautiful than he imagined. Ildiko, resigned to her fate as wife to a husband neither familiar nor human, leaves behind all she's known to embrace a man shrouded in darkness but with a soul forged of light.