I don't think its possible. Unless you trade them from each game, I'm pretty sure they all only have a set number of Pokemon in each game.
catch them
A Game Shark or Action Replay.
You can only catch Zapdos in Crystal by cheating. otherwise it is not in the game
you use it the the celebi pokemon i think?
Game shark codes
blablablablablablablabla
yes, you can with a game shark or action replay
shiny Pokemon game shark code for Pokemon fire red
well do you have a game shark? or are you asking for glitches? 'cause i have both
you have to use cheats from the game shark
The most important pokemon to catch in any game is its mascot, in this case Suicune.
you can't only if u have a game shark