Rebel Fay (Noble Dead Series #5)

Magiere the Dhampir was created by a shadowy, long-forgotten enemy of many names-an enemy who the elf Leesil was trained from childhood to kill. They were brought together by the Fay to forge an alliance that might have the power to stand against the forces of dark magics. But as Magiere and Leesil uncover the truth, they discover just how close the enemy has always been...