The Gifts of Asti by Andre Alice Norton

Varta, the last priestess of Asti, lives alone with Lur, a telepath of the lizardfolk, in Asti’s isolated mountain retreat. Decadent Memphir has long since drifted away from the austere paths of Asti, and now the barbarians of Klem are sacking the city, and the smoke of its burning drifts up to the temple.