Sins of the Heart (Otherkin, Book 1) by Eve Silver
Dagan is the Underworld's most powerful soul reaper.
When one of his brothers is murdered, Dagan must use his power to hunt down those responsible for the brutal death. But he must move swiftly - and carefully - if he's to have any chance of resurrecting his brother. Yet that resurrection could wreak havoc on the mortal world.
As an Otherkin, Roxy has sworn to protect the human race and it's her mission to stop Dagan. But when she sees him face to face, her loyalties are tested as they struggle against the potent desire that threatens to consume them both...