The Goddess of Blood & Bone by Nattie Kate Mason

With a heart as black as night, Nushka was born different to her kin.

Banished by the Gods to rule over a realm of the Afterlife rife with eternal pain, she bides her time... and makes the Pitts of Moor her very own.

In this dark place, free of morals and constraints, Agnes - a former princess - is delegated to Nushka's harem of handmaidens. Faced with the choice of fulfilling the Queen of Moor's every sinful desire, or enduring an eternity of pain, she does what she must to survive.

Yearning for freedom, both wicked souls refuse to accept their dark fates...

Together, they strike a bargain, becoming the most unlikely of allies. A deadly army of monsters at their backs.

Should they succeed in their mission, unimaginable power will be theirs. Should they fail, a fate worse than death awaits.