Asrai Assassins Series by Alana Serra, Juno Wells

She feels everything. The last thing she needs is to fall for an alien who feels nothing. As an empath, Olivia can deeply feel and even influence the emotions of those around her. For years she's used this ability to heal both physical and emotional wounds, but when she's captured by aliens, a far worse fate as a pleasure slave awaits her. That is until she's rescued by an Asrai assassin. Everyone says the Asrai are heartless killers.. moreShe feels everything. The last thing she needs is to fall for an alien who feels nothing. As an empath, Olivia can deeply feel and even influence the emotions of those around her. For years she's used this ability to heal both physical and emotional wounds, but when she's captured by aliens, a far worse fate as a pleasure slave awaits her. That is until she's rescued by an Asrai assassin. Everyone says the Asrai are heartless killers... so why can't she seem to stop herself from wanting one? Do the job. Question nothing. Feel nothing. Those are the tenets Drayek has been trained to live by. They've never failed him... until he meets the one human woman who changes everything. She's the absolute antithesis of everything he should want, yet he longs to be the source of her passion. When Olivia hires him for a deeply personal job, Drayek knows he should refuse. It's too dangerous; to easy to want things he can't have. But denying his steadily-growing interest only makes him only makes him want her more. It would be easy to resist... if they weren't constantly being hunted. But the come-down from an adrenaline high is always an emotional roller coaster. Even more so for an empath and the coldhearted alien who's starting to feel everything. less

Hunted by forces she can't fight alone, her only salvation is in the arms of an alien assassin. Alexis has spent most of her life on the run, but it's impossible for an empath to avoid forming attachments. There's no way she can abandon her friends, even if her loyalty means putting herself in danger. The solution? Hire protection in the form of a coldhearted killer. By Asrai standards, Zedrik is defective... moreHunted by forces she can't fight alone, her only salvation is in the arms of an alien assassin. Alexis has spent most of her life on the run, but it's impossible for an empath to avoid forming attachments. There's no way she can abandon her friends, even if her loyalty means putting herself in danger. The solution? Hire protection in the form of a coldhearted killer. By Asrai standards, Zedrik is defective. His people feel nothing, yet he's always had the stirrings of emotion and enough curiosity to wonder what if. So far, he's kept it under control. But when he's suddenly faced with a determined, fiery empath who's willing to sacrifice herself to protect her friends, he can't say no. With the Federation after them both, Alexis will have to trust someone to save her for a change. But is an "unfeeling" assassin the man to do it? If he turns his back on his feelings, he could finally secure a place among his people. All it will cost is the empath he's learning to love. less