The US release dates for obtaining Oak's Letter to your games has been announced by the official Pokemon website. From September 28th through November 8th, you'll be able to download Oak's Letter from the Nintendo WFC.
- You must have obtain the Pokedex from Professor Rowan in game.
- You must have no more than two wonder cards. If so, then delete one.
- You must make sure you have enabled the Mystery Gift option.
- Go to the Jubilife TV Center.
- Talk to the man who accepts messages on the second floor.
- Input Everyone Happy and WiFi Connection when prompted.
- Save your game.
- At the start up screen, there Mystery Gift is now activated.
- Under Mystery Gift, select "Receive Gift" and from "Via Wireless".
- Select "Yes" when prompted, and a wonder card will be downloaded.
- Start a game, and make sure you have an empty slot in your team.
- Go to any Pokemart, and talk to the deliveryman in front of the counter.
- You will receive your new Oak's Letter.
- Make sure to save your game.
With Oak's Letter, head to the end of route 224. The area will be different from before, and then Shaymin (in its land form) will appear. After that, follow and battle it. It will be at level 30. In your Platinum game, you can take Shaymin to Floraroma Town to gain access to the Gracidea in order to change it to its sky form.
Pokémon Platinum Version