Bit*h of the Abyss

Cassandra Watford is the only black ranked magic user in the world, the most powerful witch to have ever existed. For the people of her age she is the Witch of the Abyss, She Who Ended War, the Wall Against the Tide. For the demons, she is the Jewel of the Abyss. For the army, she is Major Cassandra Watford, tactical asset for the National Nuclear Defense Program. For the few who still really know her, she is a mess of a woman barely holding herself together. Tired of it all, on the day of her thirty-third birthday, she decides to screw it all for the better, and give herself to one of the thirteen dark gods of the Abyss, the Queen of Torment, Xhilandia. — Description from novelcodex.org