Great Rocket's Mewtwo

Pokémon Power Dark Wave Whenever 1 of your Pokémon with Dark in its name does damage to any Pokémon with an attack, flip a coin. If heads, flip another coin. If the second coin is heads, that attack does 20 more damage. If the second coin is tails, that attack does 10 more damage. If you have more than 1 Great Rocket's Mewtwo in play, use only 1 Dark Wave for an attack. This power stops working while Great Rocket's Mewtwo is Asleep, Confused, or Paralyzed.(Pokemon Card GB2: Here Comes Team GR! 2001)