First you have to beat the main story
The only way to get shaymin is to do the event in pokemon Platinum/Pearl/Diamond and to transfer it to pokemon black/white
You cannot trade between the new games of Pokémon Black and Pokémon White and the previous games of Pokémon Diamond and Pokémon Pearl and there is no way for you to trade Pokémon from "Pokémon Black or Pokémon White" over to Pokémon Diamond or Pokémon Pearl. But you can transfer any Pokemon from the old ds games TO black or white .
The fastest way is to collect every pokeon in dimond /pearl or platinum then transport every last one to black and white then collect every black and white native pokemon
you get zekrom in Pokemon white version and resheriham in Pokemon black.(in my oppinion, it should be the other way around, zekrom in Pokemon black, and resheriham in Pokemon white version) IT IS JUST LIKE PUTTING DIALGA IN POKEMON PEARL AND PALKIA IN POKEMON DIAMOND.
No, you cannot directly, but Firered Pokemon can be one way transferred to Diamond, Pearl, Platinum, Heartgold, or Soulsilver. They can then be one way "Poketransferred" to Black and White from those games.
Vullaby is not featured in Pokemon White, only Pokemon Black. The only way to obtain it in White is to trade it from Pokemon Black.
there are no other regions in Pokemon black or white.
you can't get the pokemon off of pokemon black on diamond, but you can do it the other way around.
In Pokemon Black Version the legendary is Reshiram and Pokemon White its Zerkrom.The only way to get both is to transfer Zerkrom to Pokemon Black Version or Reshiram to Pokemon White Version.
no you cant,the only way you can get pickachu is by transfering in from pokemon diamond,pearl or platinum
No. No you can't. but you can transfer the other way around. go to the poketransfer lab (east of nuvema town) for more details.
you cant. the only way to get there is if your friend has pokemon white and you use entralink.