The League Series by Sherrilyn Kenyon

In the Ichidian Universe, The League and their ruthless assassins rule all. Expertly trained and highly valued, the League Assassins are the backbone of the government. But not even the League is immune to corruption . . .

Command Assassin Nykyrian Quikiades once turned his back on the League—and has been hunted by them ever since. Though many have tried, none can kill him or stop him from completing his current mission: to protect Kiara Zamir, a woman whose father’s political alliance has made her a target. 
As her world becomes even deadlier, Kiara must entrust her life to the same kind of beast who once killed her mother and left her for dead. Old enemies and new threaten them both and the only way they can survive is to overcome their suspicions and learn to trust in the very ones who threaten them the most: each other.

n a universe where assassins make the law, everyone lives in fear—except for Syn. Born of an illicit scandal that once rocked a dynasty, he always knew how to survive on the bloodthirsty streets. But that was then, and the future is now...

Syn was raised as a tech-thief until his livelihood uncovered a truth that could end his life. He tried to destroy the evidence, and has been on the run ever since. Now trained as an assassin, he allows no one to threaten him. Ever. He is the darkness that swallows his enemies whole.

Shahara Dagan is the best bounty hunter in the universe. When Syn comes back on the radar, she’s the only one who can bring him to justice. There’s only one problem: Syn is a close family friend who’s helped out the Dagans countless times. But if she saves him, both of their lives will be on the line. Is Syn’s protection worth the risk? The only hope Shahara has is to find the evidence he buried long ago. Now it’s kill or be killed—and they, the predators, have just become the hunted...

In the Ichidian Universe, the League and its ruthless assassins continue to keep rule. But at what cost? Welcome back to the future…and a whole new world.Devyn Kell spent his life in service to the League until he learned of the double dealing and backstabbing that was costing innocent people their lives. Refusing to play those politics, he became a Runner—someone who makes sure planets get the weapons, medicine and supplies they need to survive. May the gods have mercy on any who get in his way, because he definitely won’t.Alix Garran is a woman on the run from a past she can’t escape. Signing on to work for Devyn as a System’s Engineer, she finds a cause she can fight for—and a man she can respect. But as Alix’s past catches up to her, and Devyn’s old enemies turn lethal, they have to fight together…or fall alone.

Just when you think you have it all figured out, life belts you to the ground. And when Caillen discovers a truth he'd never suspected about himself, everything in his life is turned on its head.

Desideria has a secret of her own- one that could end her life if anyone ever learns it. The last thing she expects is to meet a criminal in her sheltered world never mind find herself marooned on a hostile colony with him while his enemies try to kill them both.

And as they struggle to survive, her father's favorite curse resonates. "May you get exactly what you want and live long enough to regret it."