The Darkest Passion by Gena Showalter — book slip

Aeron, an immortal warrior cursed with the demon of Wrath, has been haunted by the presence of an invisible female. Olivia, an angel-demon-assassin, was sent to kill him but fell from the heavens, choosing to protect him instead.

As Aeron grapples with his attraction to Olivia, he must navigate a world where trusting her could endanger them all.

With an enemy on his trail and his demon companion determined to remove Olivia from his life, Aeron is caught between duty and desire. Can he trust Olivia, or will her presence unleash his darkest passion?