Nymphali

You might be wondering some things about this story; where is Oishi? Where in comparison to Equestria? Why don't Pokémon exist in Equestria if they do exist in the pony universe?

They teach it in history class. Long ago, before the banishment of one of Equestria's many princesses, forgot which one but apparently a bunch of weird guys in your universe are obsessed with her, Pokémon were a thing in Equestria. Not major like they are here, just another thing, like apple farming and party planning. Treated just like normal animals mostly, trained by some, a couple specific laws because they're dangerous sometimes.

Then legendaries were discovered, and they were WAY dangerous, especially this bacon bird thing that kept killing random ponies. Instead of making more laws, the ruler Princess Trollestia or whatever just set up a campaign to capture and destroy every single Pokémon.  This obviously bothered some ponies, who started a rebellion, led by a pegasus who was said to resemble the Reshiram she trained. Princess Celsius or something realized the power of the revolution was greater than hers, so she captured a Pokémon of her own, against its will. Arceus, the Alpha Pokémon. This scared the crap out of the revolution, and the Reshiram pegasus signed a truce for the revolution to become its own nation with Pokémon allowed in exchange for being forgotten forever, despite sharing borders with Equestria.

And so the Pokémon Nation was born. Split into various regions for various purposes, all Pokémon in Equestria were relocated to the Nation. Reshiram Trainer Pony put the capital here in Oishi, and was promptly elected Champion. It's said that she still has descendants today.

The More You Know