Like it says in the rules. For beating the Gym Challenge portion, you'll receive a 5-6IV Pokémon of your choosing bred by me. If you defeat the Elite Four you'll be able to choose one of these Pokémon below and it will be holding a Master Ball (while supplies last on those.) All of these are in my Pokémon Home and I've collected them since Pokémon Black and White and transferred them over the years through my games, Pokémon Bank and now into Home. So if you want one I can't transfer into Sword and Shield, you'll have to have Pokémon Home.