The world was ravaged and there were barely a few survivors among all races.
From a billion, only several million of the human race were left after the long-lived races went berserk.
Meanwhile, from a million, the population of the long-lived race dropped to a hundred thousand after humanity's plot.
But after they went berserk and self-destructed, the long-lived races left were less than fifty thousand. And this number included nature spirits which were the greatest number of survivors.
Nature spirits usually blend in with their natural habitats so humans did not know how to kill most of them. Thus, they were the ones who survived with the most number.
Due to this tragedy, the gods had to make an ultimatum so this won't happen again. They decided to separate their creations. The long-lived races would no longer live among the humans. The short-lived humans would rule among themselves.