Fixing worlds (Requesting for an alternate title)

A random person from our world is selected as a champion, by a being who looks over all worlds, and is given a mission to enter the worlds which are fated to be destroyed and save them from destruction. . . Starting world : TDG . . . . If the above synopsis doesn’t make sense then don’t worry, that’s just me trying to write a synopsis that feels like the ones on the Chinese novels. . . Simpler synopsis : A guy goes to xianxia/wuxia worlds with the storyline where the mc is dead to essentially replace the protagonist or work with him (depending on the world) to prevent the world’s destruction and live happily ever after. Do not expect regular updates as I am not a proper writer.