Japan is Getting Awesome Pokemon-Themed 2DS Consoles
The best official way to play Pokémon Crystal because the save battery won't die and you can now transfer to a 3DS game for free, also restored Celebi and wireless battling :
Is there a Pokemon Sword and Shield 3DS version? - GameRevolution
Will Pokemon Sword and Shield be on Nintendo 3DS? | Shacknews
New Nintendo 2DS XL - Bulbapedia, the community-driven Pokémon encyclopedia