Are You There, Old Gods? by Evan Williamson
No one ever told Kan that life in the Pit would be so confusing. When her blood pack moves from the City of Pain to the Pit, she has to adjust to life in a dark hole, a dank learning cloister, and a changing body. Kan knows she needs someone to talk to about spells, belief, and subjugating everyone around her, and it is not long before she's found a solution.