Creterampage
Every 1000 years, the gods of religions from all over the world come together to decide if humanity should live for another 1000 years, or if they should be exterminated. Considering the past 1000 years, the gods have determined humanity is an irredeemable species that must be wiped out. Right before they make this decision official, the Valkyrie Brunhilde steps in. She proposes that the gods give humanity one last chance through "Ragnarok", a tournament between 13 gods of legend, and 13 legendary humans from history.