You can't have more than 1 Shining Mewtwo in your deck
If an attack does damage to Shining Mewtwo during your opponent's next turn (even if Shining Mewtwo is Knocked Out), flip a coin. If heads, prevent all damage done to Shining Mewtwo from that attack (any other effects of attacks still happen) and do 20 damage to the attacking Pokémon.
Discard a Energy card attached to Shining Mewtwo or this attack does nothing. This attack does 40 damage plus 10 damage for each Energy attached to the Defending Pokémon.