Jaga's Bones by Simon McHardy
Jaga is abandoned by her father to the dark female order, the Sisters of Gloam, a dumping ground for the sick and depraved. She must survive the horror trials of torture and abuse and her murderous classmates just to end up part of a ruthless invasion force that kills first and asks questions later.
Taron, a crippled farmer in possession of a demonic and sexually frustrated axe, must fight to save his homeland from the sisterhood and try not to pick up too many bad habits or sisters along the way.
This book contains graphic violence and sex scenes.