Return from the World of Pokemon

[Pokemon arrive in the real world + realistic Pokemon setting + transmigrate to the spirit world + return to Earth] Note: The author loves changing things up and has altered a lot of the original setting. If that's not your thing, please don't read! After spirit creatures arrive on Earth, the protagonist is transmigrated to their world during a spatial disturbance! He becomes a Pokémon Hunter there, then returns to Earth several years later. Only one year has passed on Earth... People are still afraid of and unfamiliar with these amazing creatures called Pokemon, and most want nothing to do with them. To ease people's fear of Pokemon and prevent a war between them and humanity, he decides to announce to the world, as someone who has returned from the other world, that the Pokémon League will be established today!