The Brush of Black Wings by Grace Draven — book slip

During a foray into the woods of Neith, Martise stumbles upon a ruined temple and reawakens not only a power she thought lost, but also something far more malevolent.

An ancient darkness, imprisoned in an eternal cage, sees a chance at freedom in a woman once held in bondage.

Desperate to save her, the Master of Crows will break the barriers of time and worlds to challenge an entity born of forgotten magic and the remnants of souls—a demon king who once led hordes of the damned across the face of the world.

The destroyer of gods will battle the destroyer of men to reclaim her and discover a truth the keepers of history once conspired to conceal. A tale of revelation and redemption.