Aether’s Mark by Rachael Slate

He wields the power of Aether, but she will leave him enamored
She guides the paths of others

Minthe of the Asteriae, star nymphs, possesses the power to light the paths of lost souls. The only future she can’t navigate is her own. After being imprisoned by the ruthless Lapith King, she’s instructed to aid her rescuer—an enticing stranger from a faraway land who desperately needs her clarity. Yet his haunting past and the nebulous future before him are both so uncertain, helping him threatens to extinguish her own light.

His mark is written in the stars
Eagle shifter and Master of the Aether, Lord Rhoetus lives in the in-between. As the rightful King to the centaur throne of Krete, he knows his destiny and his path, until a fiery nymph challenges him with another future. On the verge of an unforgivable act of betrayal, he’ll have to choose between his mate and his Kingdom, because he can never have both.
Trapped in the starlight of their fates

War descends and even the light of their love might not be enough. When Rhoetus and Minthe fall victim to the darkness lurking inside them, saving their world means first saving each other.