Dark Siren by Eden Ashley

Kalista guards a dark secret that has never allowed her to fit in. She is a siren. Instead of luring men to shipwreck, Kalista sucks the very life force from their souls. From day to day she never knows from where her next meal will come, but resists the urge to feed for as long as possible. And then Kalista meets Rhane. Strange and familiar all at once, she immediately forms a smoldering connection to this handsome young man with otherworldly eyes, and feeding from his life force begins to change her in unexpected ways. Soon, Kalista learns that Rhane is guarding terrible secrets of his own. Secrets tied to a long forgotten past. Secrets that could lead to the undoing of them both. And yet, somehow they must save each other.