Despite Mortal Sins by Anna Hawke

Death may shatter a soul, but a Reaper picks up the pieces.
In the span of a single, bloody hour, Rukia’s world collapses. Outwitted by their enemies, their resulting brutality thrusts her into a role she never wanted. Devastated and mourning, she’s forced to come to terms with the changing face of Elemental society—and the man who is her fated mate.

As a Reaper, Isaiah embodies living death, holding the power to claim a soul with a single touch. After centuries of shielding himself for the sake of others, his defenses are breached by a woman vulnerable to his vicious abilities. When one tragedy spurs another, Isaiah must decide if Rukia’s love is worth risking her life.

Neither can fight against the feral desire that burns between them—nor the need for revenge against those who’ve wronged them. But demanding penance for the sins of their enemies risks an eternal cost, and the next day is never guaranteed.
As their lives crumble around them, everything will either fall into place—or into pieces.