Dragonfell. Riders of Drakefall Series, #3

The sacred groves of Erthea are falling. One by one, ancient sites of power are being twisted into something dark. Not destroyed-transformed. And at their heart lies a force that doesn't just break magic. it rewrites it. Summoned home as a Valeran, not a rider, Bree is forced back into a world that no longer trusts her. The corruption beneath her skin marks her as dangerous, unstable, something to be feared-not followed.
But she's the only one who understands what they're facing. As void rifts spread and a hidden enemy orchestrates the collapse of Erthea's foundations, Bree must lead a fractured alliance of riders, scholars, and fae into a battle no one else is prepared to fight. Because this isn't an attack. It's a ritual. And when the final grove falls, the world won't survive what rises in its place. To stop it, Bree will have to embrace the very power that's tearing her apart-and risk becoming the thing her people fear most.