From the Back Cover:
Challenged by Darkness and Light
Abducted by demons, Sera Valence damned herself to save those she loved. Now the queen who claimed her soul has conscripted her into a war she cannot win, against a foe she cannot possibly defeat. Trapped in a realm of madness and torture, Sera must fight for her soul and countless others.
Meanwhile, in the Five Provinces, a golden army from a divine otherworld seeks to unite the world by erasing its people. To stop them, all Kara Honuron must do is become a Soulmage, restore the power of broken gods, and recover the soul of her mortal enemy … a soul who does not want to be found.
Two friends must wage two wars, one against the darkness and one against the light, yet victory offers no salvation, only sacrifice. And defeat means the end of everything.
(Spoilers for Book 1 – Glyphbinder Follow)
(Spoilers for Book 2 – Demonkin Follow)