Azazel. Alien Legacy Brotherhood, #4

He was sent to rescue her, but she may be the only one who can save him from himself. Azazel is a psychic warrior, one of five brothers engineered for a battle that was lost millennia ago. Now, he has a new mission: infiltrate a soul-crushing alien mothership and rescue a captured human female. But the oppressive psychic energy of the Krystalii invaders awakens the one thing he fears most-the savage, uncontrollable beast chained within his soul.
To succeed, he must maintain absolute control. But one look at the woman he's meant to save, and the beast roars in recognition.*Mate*Toni Choi traded her soul-sucking Hollywood job for a once-in-a-lifetime adventure, only to be abducted and imprisoned by a galactic tyrant. Now, she's a pawn in a terrifying genetic experiment. When a dark, powerful warrior with haunted eyes appears in her cell, she doesn't know if he's a savior or a more dangerous kind of trap.
But as they're thrown together in a desperate escape, Toni discovers a shocking secret: she has an uncanny connection to the enemy's technology, a gift that could turn the tide of a galactic war. Trapped in the heart of enemy territory, their only hope is the undeniable, searing bond that ignites between them. But to protect her, Azazel may have to unleash the very monster he's sworn to contain. And to survive, Toni must place her trust in a man whose inner demon could be their salvation.
or their ultimate undoing.