The Wolf and the Woodsman by Ava Reid
In her forest-veiled pagan village, Evike is the only woman without power, making her an outcast clearly abandoned by the gods.
When soldiers arrive from the Holy Order of Woodsmen to claim a pagan girl for the king's blood sacrifice, Evike is betrayed by her fellow villagers and surrendered. But when monsters attack the Woodsmen and their captive en route, slaughtering everyone but Evike and the cold, one-eyed captain, they have no choice but to rely on each other. Except he's no ordinary Woodsman - he's the disgraced prince, Gaspar Barany, whose father needs pagan magic to consolidate his power.
Gaspar fears that his cruelly zealous brother plans to seize the throne and instigate a violent reign that would damn the pagans and the Yehuli alike. As the son of a reviled foreign queen, Gaspar understands what it's like to be an outcast, and he and Evike make a tenuous pact to stop his brother. As their mission takes them from the bitter northern tundra to the smog-choked capital, their mutual loathing slowly turns to affection, bound by a shared history of alienation and oppression.
However, trust can easily turn to betrayal, and as Evike reconnects with her estranged father and discovers her own hidden magic, she and Gaspar need to decide whose side they're on, and what they're willing to give up for a nation that never cared for them at all.