The demon lord won. The Chosen One is dead. The gods were cut off from the world. The hero, no matter what, fell. The world is doomed and can never be saved. However, there is still a small hope. While what has happened cannot be fixed, hopefully it can be prevented from happening in the first place. The heroes are allowed to try to right things again, with just a few changes to their stories.
Heroes try again and again, through life after life, against odds they think are impossible. In a final desperate gamble, they gave up everything they had gained, their title of hero, their power and their birthright, for a new chance knowing all their failures.
But if legendary heroes have all their divine abilities, how can a little girl save the world?