Chaos Etched in Flesh by Lyn Gala

Kilian Kildare is a soldier, fighting the witches and vampires who twist the gift of magic into something dark. However tragedy after tragedy have left him struggling—he’s been turned into a vampire, ostracized, and left to grieve alone. An offer to join an elite Army unit should be the answer to prayers he no longer dares to say. Instead, the move brings new dangers, and new pain.
A demon has slipped its leash, killed its summoner, and now hides within a host. The only barrier between the demon and a world unprepared for its pure veil magic is the fragile flesh of a man Kilian had once cared for. The demon is seeking a way to either kill or corrupt Stephen to escape, and Kilian finds himself guarding a man he’d rather save. When Stephen and the Army end up on opposite sides, Kilian has to choose between them, a decision made nearly impossible because he’s not sure which side is actually protecting the world, and which may bring about destruction.