I Won't Be the Protagonist, Right?

Changsheng is an immortal person. Even if someone chops him into clay, he will slowly come back to life. Don't ask him how he knows. Changsheng thought he would live like this until the end of the world, but after waking up, he found that the world had changed... "I seem to have become the protagonist?" Changsheng muttered to himself as he looked at the thing that fell out of the sky inexplicably in front of him.