trade with somebody
It's kinda impossible to get a Ditto without an National Dex, unless you hack the game with the Action Replay to get it.
a cirtificate saying you completed the game
Ditto in platinum appears in the trophy garden. If you save before you talk to the owner of the trophy garden, you can talk to him. if he does not say he saw a ditto then restart the game and reapet it until you do. Hope this helps!!!
You cannot. You will only have one Master Ball in the game. Unless you used cheats..
Ditto is in the giant chasm ounce you beat the game
No, because Ditto is not in Sinnoh Pokedex, but if you trade with your friends, then you can get Ditto. Unless if your friends don't give it.
You beat the game by completing the browser, defeating Darkrai, befriending all partner Pokemon, completeing all the secret and extra missions, and completeing all the jobs that people ask you to do.
You can get ditto in route 218 by using a pokeradar i think?
No Ditto cannot evolve unless they make a Pokemon game which allows it to evolve
with a chicken
no.
RESENGAN!!!!!!!!!!!!!!!!!!!!!!!!!!