redeemer

From Middle English redemer, redemar, equivalent to redeem +‎ -er.

redeemer (plural redeemers)

1. One who redeems; one who provides redemption.
   • 1920, Edward Carpenter, Pagan and Christian Creeds, New York: Harcourt, Brace and Co., published 1921, page 137:

     However there is little doubt that Virgil did - in that very sad age of the world, an age of "misery and massacre," and in common with thousands of others - look for the coming of a great 'redeemer.'

   • 2018 May 4, Tom English, “Steven Gerrard: A 'seriously clever or recklessly stupid' Rangers appointment”, in BBC Sport‎:

     With no experience in management, little knowledge of life in Scottish football, a dressing room to gut and replace, Gerrard is now cast in the role of Rangers' great redeemer. Whatever fate befalls him, this will not be dull.