The Demon's Vow by Jamie Peterson
She was meant to be his weakness. He became her only protection.
Eira never believed in demons-until one saved her life.
Cursed with a mysterious mark and hunted by creatures that shouldn't exist, Eira's world spirals into chaos when a powerful demon named Kael makes a vow to protect her. Bound by an ancient oath and haunted by a past drenched in blood, Kael's presence is both her salvation and her greatest danger.
As their worlds collide, desire ignites-and so does the threat of damnation. Kael is forbidden to feel, forbidden to care... but every moment with Eira tests the limits of his vow and the darkness that lives inside him.
When enemies rise and secrets unfold, they must decide: will their bond save them-or destroy everything they've ever known?
Dark. Addictive. Unforgettable. The Demon's Vow is a supernatural romance where loyalty cuts deeper than any blade and love can cost you your soul.