Heir of Fire- Sarah J. Maas

Celaena Sardothien has survived deadly contests and shattering heartbreak, but now she must travel to a new land to confront her darkest truth. That truth could change her life - and her future - forever. Meanwhile, monstrous forces are gathering on the horizon, intent on enslaving her world. To defeat them, Celaena will need the strength not only to fight the evil that is about to be unleashed but also to harness her inner demons.