People think Mewtwo is weak. I don't. Here is why: Let's say a Charizard with 12 energy cards attached to it knocks out your Pokemon and you send out Mewtwo. Now use Psychic! If you read Psychic, it says that you do 10 damage + 10 DAMAGE FOR EACH ENERGY CARD ATTACHED TO THE DEFENDING POKEMON! Therefore, Mewtwo is DEADLY if your opponent has a lot of energy cards attached to his/her pokemon!