Dark desires after dusk - Kresley Cole

Nothing will stop Cadeon of the Rage Demons from finding the means to atone for the one wrong that haunts him. But once he captures the key to his redemption, the halfling Holly Ashwin, he finds that the woman he thought he could use for his own ends and then forget haunts him as much as his past.
Raised as a human, Holly Ashwin never knew that some legends are real until she encounters a brutal demon, who inexplicably guards her like a treasure. Thrust into a sensual new world of myth and power, with him as her protector, she begins to crave the Cade's wicked touch.
Yet just when he earns Holly's trust, will Cade be forced to betray the only woman who can sate his wildest needs - and claim his heart?