- Select Mystery Gift on the main menu.
- Select Receive Gift, then Yes.
- Select Get via Internet, and then Yes.
- Speak to the delivery girl in any Pokémon Center to receive Diancie.
- Save the game.
Don’t wait, though—Diancie will only be available until July 27. It’ll come with a Diancite Mega Stone, which will allow it to evolve. Diancie’s characteristics are:
Type: Rock, Fairy
Abilities: Clear Body
Weaknesses: Steel, Ground, Grass, Water
Height (ft): 2′ 4″
Weight (lbs): 19.4
Moves: Diamond Storm, Moonblast, Dazzling Gleam, Protect