An apostate was a member of a religious order who was expelled for breaking the rules of their faith. The Sorcerers of Tund expelled those who embraced the dark side of the Force, dubbing them apostates. Once such apostate sorcerer attacked and butchered a village on Kiffar, generating a deep shame in the rest of his Order. A Mandalorian that belonged to the Children of the Watch and broke the Mandalorian Creed would become an apostate According to Creed, one may only be redeemed in the Living Waters beneath the mines of Mandalore. The Mandalorian Din Djarin removed his helmet and was considered apostate by Paz Vizsla and The Armorer. Djarin also considered himself an apostate, although the Magistrate of Nevarro Greef Karga promised him that on Nevarro he is not considered apostate and could be landed gentry.
In order to remove his decree of exile, Djarin went on a mission to the Living Waters. After being captured in the ruins of Sundari by a Spider Tank, he was rescued by Bo-Katan Kryze, who later helped him bathe in the Living Waters. They returned to the covert and showed a proof from the Living Waters to the Armorer, who confirmed that they were redeemed and no longer apostates.