Bow Before the Elf Queen by J.M. Kearl — book slip

Layala has spent her life in hiding, preparing for the day when the wicked High Elf King Thane would come to claim her as his powerful mate. Trained to avenge her parents' wrongful execution, she is determined to fight back.

But when Thane finally arrives, a dark-haired warrior king intent on marriage, Layala finds herself captured and unable to kill him due to a secret he holds.

As she plans her escape, Layala must confront her own dark truth that makes their love forbidden, even as Thane's desire for her grows.

For fans of Hades & Persephone retellings and The Lord of the Rings.