The Unspoken Name by A.K. Larkwood

The Serpent Gates, Book 1

Does she owe her life to those planning her death?

Csorwe was raised by a death cult steeped in old magic. And on her 14th birthday, she’ll be sacrificed to their god. But as she waits for the end, she’s offered a chance to escape her fate. A sorcerer wants her as his assistant, sword-hand and assassin. As this involves her not dying that day, she accepts. 

Csorwe spends years living on a knife-edge, helping her master hunt an artifact which could change many worlds. Then comes the day she's been dreading. They encounter Csorwe’s old cult - seeking the same artifact - and Csorwe is forced to reckon with her past. She also meets Shuthmili, the war-mage who’ll change her future. 

If she’s to survive, Csorwe must dodge her enemies, claim the artifact and stop the death cult once and for all. As she plunges from one danger to the next, the hunt is on.... 

Very good condition.