Oops, I Became a World BUG

This is a post-apocalyptic different world that has experienced the "Great Nirvana" event, which caused the heavens to collapse, spiritual energy to rage, and the world to fall into a ruined era of rust and mechanical decay. The sky is purple-red, and the land is barren, littered with metal wreckage, abandoned floating ships, ancient ruins, and mutated monsters. Humans struggled to survive in the ruins, forming city-states, settlements, and raider gangs. The world is filled with cold machines, violent energy and cruel laws of survival.