Once upon a time, there was a pokémon called Arceus who created the world of pokémon we see today, the lake trio, and the creation trio. It was dubbed as "The Original One" and "The God".
However, after decades, the original one grew bored, and unsatisfied with the world no matter how many pokémon it created. Until one day, a young girl was born and caught the eye of the all mighty, who put a claim on the girl as its loyal subject, even if it meant bending its own rules to ensure the girl would not die on each journey she went through.
Johto, Kanto, Hoenn, Sinnoh, Unova, Kalos, Alola, Galar, and even Ancient Hisui, all regions completed, but the girl could not escape the never ending trauma she endured. Now, she travels through Paldea.