There is a SPECIAL mewtwo event: It will have psystrike, shadow ball, aura sphere, and the special: electro ball!
Held Item: King's Rock
Ability: Pressure
Has a Premier Ribbon
Is a Fateful Encounter
OT NAME: FEB2012
OT ID: 02112
You already know you'll need a copy of Pokemon Black or White and some Version of the Nintendo DS. Also, you can't have more than 11 Wonder Cards in your possession to get the Mighty One. You'll also need a Wif-Fi connection.
1
Start the game and select MYSTERY GIFT on the menu screen.
2
Select RECEIVE GIFT then hit "Yes" to open a communication channel.
3
Now, select GET VIA NINTENDO WFC and hit "Yes".
4
Now you're receiving the genetic abomination.
5
You'll need to have a least one open slot in your party.
6
Pick up the Mewtwo by speaking to the deliveryman in any Pokemon Center.
7
After speaking to the delivery man, Mewtwo will be in your party.
8
Don't forget to save!