You can't but you can get a action replay and use its cheats or if you have wi-fi you can go to GTS in jubilife city and trade find a person who has one up for trade or you offer a Pokemon for one
Mewtwo cannot be obtained in the wild, without the use of a cheating device such as Action Replay. However, it can be received from trades. If you own Pokemon Leaf Green or Fire Red for the Gameboy Advance you may import Mewtwo into Pokemon Platinum after catching it in Cerulean Cave.
use action replay .
You have to get surf then surf from jublife city
Crystal does not have Mewtwo. Instead it has Ho-oh after you beat the Pokemon league.
Mewtwo, yes, if you have a FireRed or LeafGreen with Mewtwo.
you can only get darkria in Pokemon platinium if you get the wonder card that was a Pokemon event last year.
In fall 2009
Route 201 (Dongle)
I Think its Pokemon Diamond and Platinium
You can't get Mewtwo in Pokemon Pearl.
yes,mewtwo is in Pokemon dimond/pearl
how do you catch a mewtwo on Pokemon platinum