Team Rocket's Mewtwo ex (Japanese) - 043/M-P - Promo from M-P Promotional Cards, available at 401 Games Canada.

• Rarity: Promo
• Finish: Holofoil
• Artist: aky CG Works
• Card Text:
  Ability: Power Saver This Pokémon can't attack unless you have 4 or more Team Rocket's Pokémon in play.
  [Psychic][Psychic][Colorless] Erasure Ball (160+)
  You may discard up to 2 Energy from your Benched Pokémon. This attack does 60 more damage for each card you discarded in this way.