Love, Immortal by Eden Ashley

The Alchemy Initiative—a doomed scientist’s failed attempt to harvest human souls from the afterlife and bind them to complex machines—has been reinitiated. But it doesn’t take long to discover why the program responsible for making Ethan Remington the ultimate weapon was shut down when the spirit of the highly unstable and murderous Agent Drekker goes rogue, embarking on a sinister rampage in an attempt to claim the ultimate prize.

That prize is Ethan—everything that Ethan has and everyone who he loves. No one is safe, especially young Hogan who has begun to display some frightening and incredible abilities. To stop this insatiable evil, Ethan may have to forfeit his humanity…and even his soul.