Yeah, I really don't know whether it should be like "Pokétalia" or "Hetamon."
This would be based off of the anime Hetalia.
Go look it up if you don't know what I'm talking about.
The main character would be Sealand or Fem!Sealand, and the rival would be Wy. Professor figure would be Australia, villains would be Russia and the Baltic Trio. Maybe Belarus as well. Gym leaders would be the World 8 (America, England, Russia, China, France, Germany, Italy, Japan) and the Elite Four and Champion would be Iceland, Finland, Denmark, and Norway. Of course, Flying Mint Bunny would be a legendary.
The story would be something like this:
Sealand wants to become a distinguished Pokemon trainer, like his parents Finland and Sweden. Finland is a member of the Elite Four and Sweden is the Champion. In order to be recognized as a great trainer he decides to go on a journey, battling the 8 gym leaders and defeating the Elite Fur to become the best country/trainer out of all of them.
The order of gym leaders would be something like this: UK-France-Italy-Germany-Us-Japan-China-Russia.
All of the countries will make an appearance. The grouping of countries would be something similar to what's below.
America: Canada, Cuba, S. Korea, Molossia
France: Seychelles, Cameroon
N. and S. Italy: Spain, Prussia, India, Belgium, Netherlands, Seborga, Luxembourg
Germany: Austria, Hungary, Bulgaria, Romania, Switzerland, Liechtenstein, Kugelmugel
China: Taiwan, Hong Kong, Macau, Vietnam, Thailand
Russia: Ukraine, Belarus, Estonia, Latvia, Lithuania, Poland
Japan: Greece, Turkey, Egypt, TRNC
Nordics: Sealand, Wy, Australia, Hutt River
Of course, there'll need to be some redistribution because England is all by himself.