MC as NPC turned Survivor

Hello! I would like to ask for help on this novel I read a while ago. Basically, the MC is an NPC in the "mission" world which get dragged in as a "survivor" because he wanted a job. He was an amnesiac at the beginning of the novel but slowly uncovered his history the more he interacted with the survivors. The ML here is also the Top 1 Healer and is like a priest figure. I would appreciate it if people can find out the title. Thank you! 🙇‍♀️