Well, to catch Shaymin you must have the mystery gift Oak's Letter which was available via Nintendo Wi-Fi Connection September 28th to November 8th. Without this it is impossible to catch Shaymin. Although I don't have Shaymin I know you can catch him with Oak's Letter any time you want, whether you've just got you're starter or have completed the game (which you won't have because you're still missing Shaymin).
For those of you who have got Oak's letter this is how you get the mysterious pokemon. If you don't understand mystery gifts you have probably checked your bag, find it wasn't there and given up. But to get it you must (after supposedly receiving the letter) talk to the delivery man by the counter in any Pokemart. Now check your key items and it should be there! It's description is "A letter from Professor Oak. Written in it is a request for you to go to Route 224". Before the next step SAVE YOUR GAME! So now go to Route 224. Hopefully you should be able to do this next bit by yourself. I say this because I haven't got a clue what to do next! You will fight Shaymin in land form but to change it into sky form you need to go to Floroma town with Shaymin in your party and talk to the girl near the town sign who will give you the Gracidea which when used on Shaymin transformes it.
P.S: If I have made any mistakes in this article please note it is entirely down to my own stupidity
nothingNothing, you just have the joy of beating it.
If you beat the elite four before you catch raquaza you can use the cloning glitch to get as many master balls as you want (the reason for waiting until after you beat the elite four is because the cloning glitch takes place in the battle frontier
for the battle tower u beat the guys 21 time for all the places and for the battle hall u have to beat 51 guys or girls
beat the Pokemon league and go back to the entrance
first beat all jhoto gym leaders and champion and then go there
complete the pokedex get all badges beat battle tower etc
you have to beat the battle frontier brain
You can access the Battle Frontier and you can catch some legendary pokemon.
Get all of gold symbols from Battle frontier.
you have to beat the game 6 times without losing a battle and go to the place where you catch shaymin and oak will be there to take you to it
nothing happens. you just beat the battle frontier that's all.
Battle them and Beat them.
After you beat the elite you go to the battle frontier and find and catch all the Pokemon in the Hoenn region.
Go to the S.S tidal after you beat the league and it will say Battle Frontier
You need the simbols
When you beat the game you can go to the battle frontier and there is a spot to the right of the battle palace where an odd tree is use the wailmer pail on it and it attacks you its Sudowodoo! Catch it and your set.
beat the frontier brains