The Darkest Surrender- Gena Showalter

"Possessed by the demon of Defeat, Strider cannot lose a challenge without suffering unimaginable pain. For him, nothing stands in the way of victory--until Kaia, an enchanting Harpy who tempts him to the razor's edge of surrender. Known among her people as The Disappointment, Kaia must bring home the gold in the Harpy Games--or die. Strider is a distraction she can't afford, because he has an agenda of his own"--Dust jacket flap.