Bloodthorn by Jess Rae

Noelle Ashby was never meant to be the bride.

When royal riders come to Briarhollow to claim her younger sister for the cursed king of Thornfell, Noelle steps forward in her place. She expects a palace, a wedding, and perhaps a monster.

Instead, she finds a kingdom built on old sacrifices, a wall that hungers for brides, and a king who may be more prisoner than villain.

Caivan Thornfell was raised to be the lock on an ancient curse. Cold, feared, and bound to a throne soaked in blood, he knows better than to hope for mercy. But Noelle is not like the brides who came before her. She refuses to kneel. Refuses to be claimed. Refuses to let any crown decide what her life is worth.