Soul Reaper - D. B. Smyth - Bog

I don't save lives; I take them. Maybe tomorrow someone will take mine. Not likely, but one can hope.
Isolation.
Carnage.
Sanity wrung from the soul like water from a wet cloth.

Keres never expected this would be her life when she vowed to be an Angel of Death over a thousand years ago. All she wanted was the power to avenge her murdered family; now all she has is violence and death: slaughtering souls for God's will and purpose.

When her latest reaping is ambushed by Daemon assassins sent to annihilate her, Keres discovers the truth is not what it seems and her contract to reap souls is destroying her own.

Now she must trust the very people sent to kill her if she is to free herself from the unbreakable contract before her next reaping becomes her last.