Pokemon Brilliant Diamond Oak's Letter. This method produces boards with heavy stippling visible in the grain. In pokemon brilliant diamond shining pearlin todays video we will be going over how to get . How to get shaymin now! Although all players can receive oak's letter, you must first enter the hall of fame and obtain the national pokedex before you can encounter . Start pokémon brilliant diamond or shining pearl · begin playing the game and open the x menu · select 'mystery gift' · select 'get via internet' . Tiger oak is oak that is milled into quarters at an angle to the growth rings of the tree. Once you receive oak's letter, go talk to professor oak on route 224.