The Eternal Balance Series by Jus Accardo

Hell is looking for a way to break loose…Jax lost the genetic lottery. Descended from Cain, the world's first murderer, he's plagued by a curse that demands violence in exchange for his happiness. He left everything behind, including the girl he loved, but thriving on the pain of others is lonely… And it's killing him. After a series of heartbreaking losses, Samantha put rubber to pavement and headed for college as fast as her clunker could carry her. But she can't outrun her problems... moreHell is looking for a way to break loose…Jax lost the genetic lottery. Descended from Cain, the world's first murderer, he's plagued by a curse that demands violence in exchange for his happiness. He left everything behind, including the girl he loved, but thriving on the pain of others is lonely… And it's killing him. After a series of heartbreaking losses, Samantha put rubber to pavement and headed for college as fast as her clunker could carry her. But she can't outrun her problems. When an attack at school drives her back home, she's thrown into the path of a past—and a guy—she's been trying to forget. Sam strains Jax's control over his darkness, but running isn't an option this time. Someone—or, something—followed her home from school: a ruthless monster with a twisted plan centuries in the making. Forced together to survive, and fighting an attraction that could destroy them both, Jax and Sam must stop a killer bent on revenge. less

Descended from Cain, the world's first murderer, Jax Flynn is destined to spend his life making others suffer. To shield the world from horrific chaos, he was forced to sacrifice the one and only thing he loved. Samantha Merrick.Sam is special. She doesn't know how—or why—and she hasn't had any luck finding out. But there's a bright side to her life. She finally has Jax back. Sort of... moreDescended from Cain, the world's first murderer, Jax Flynn is destined to spend his life making others suffer. To shield the world from horrific chaos, he was forced to sacrifice the one and only thing he loved. Samantha Merrick.Sam is special. She doesn't know how—or why—and she hasn't had any luck finding out. But there's a bright side to her life. She finally has Jax back. Sort of. They're living life on a strict look but don't touch policy, but with the explosive chemistry between them, keeping their hands to themselves is getting harder every day. Unfortunately, keeping their libidos in check isn’t Jax and Sam's biggest problem. When an enemy from the past resurfaces with an ultimatum—complete a simple task or Sam dies—they're backed into a corner. The goal? Kill a demon called Malphi. The problem? Jax's demon, Azirak, has no intention of letting that happen… To gain a chance at heaven, they’ll need to embrace hell… Series order:Eternal Balance Book 1: Ruined Eternal Balance Book 2: EmbraceEternal Balance Book 3: Released less

Jax Flynn’s life just went from bad to worse. He was already sharing his body with a demon named Azirak, but after killing its mate… Well, shit got real. Now the demon has taken control of Jax’s body and everything he cares for is at stake, including Samantha, the girl he loves. Yeah, that’s not going to happen. It’s time Jax showed everyone what he was really made of.