Fireborn Series by Aisling Fowler

Lyra. Lucy. Percy. Once in a generation, a hero emerges whose story enthralls readers worldwide. Ember is full of monsters. Twelve gave up her name and identity to train in the art of hunting them--so she says. The truth is much more deadly: she trains to take revenge on those who took her family from her. But when Twelve's new home is attacked, she'll find herself on an unexpected journey, where her hidden past is inescapably intertwined with her destiny--and the very fate of her world.

Phoenix and her friends vow to save Ember from all but certain doom in this final unmissable chapter in the sweeping series that  New York Times  bestselling author B. B. Alston called “the best kind of children’s fantasy story.” Following the shocking events at Icegaard, Phoenix and her friends gather with the Hunters, desperate to unite the warring clans before their enemy, the Master, launches his attack on Ember... morePhoenix and her friends vow to save Ember from all but certain doom in this final unmissable chapter in the sweeping series that  New York Times  bestselling author B. B. Alston called “the best kind of children’s fantasy story.” Following the shocking events at Icegaard, Phoenix and her friends gather with the Hunters, desperate to unite the warring clans before their enemy, the Master, launches his attack on Ember. The Cavern of Light offers hope in the form of a legendary weapon, but the friends must brave the unknown, facing down new and deadly creatures in search of the artifact that could save their world. As an epic final showdown draws near, Phoenix is determined not to lose anyone else that she loves. But the Master is more brutal and powerful than she ever imagined, and as Phoenix’s past and present collide, unthinkable sacrifices will have to be made to defeat him. less