The Poké Ball Plus contains the Mythical Pokémon Mew when purchased new. If you link up a new Poké Ball Plus to Pokémon Sword or Pokémon Shield, you’ll be able to receive Mew in the linked game.
Notes: The Poké Ball Plus will be sold separately from the actual games.
Unlike in Pokémon: Let’s Go, Pikachu! and Pokémon: Let’s Go, Eevee!, you will be unable to use the Poké Ball Plus as a controller in Pokémon Sword and Pokémon Shield.
If you have already received Mew in Pokémon: Let’s Go, Pikachu! or Pokémon: Let’s Go, Eevee!, you will be unable to receive Mew from the same Poké Ball Plus in Pokémon Sword or Pokémon Shield.
You will only be able to receive Mew once per Poké Ball Plus. If you received Mew in a separate save file, or deleted the save data in which you received Mew, you will not be able to receive it a second time.