Deities

This is a time way before Pokeballs and Pokedexes. None of the regions were created yet, but instead people were split into groups depending on what type their Pokemon partners were. But soon each groups realized that they all had weaknesses and strengths. This lead to war.

Aila, princess of the Grass Nation, never wanted her role. It's too much responsibility, and she wouldn't want to give up her partner Pokemon in exchange for her new Pokemon she'd have to keep; Celebi.

But someone discovered this fact, and Aila was abandoned. She was no longer wanted. Until she met them.