Volcarona-GX

Once during your turn (before your attack), you may discard a Fire Energy card from your hand. If you do, put 2 damage counters on 1 of your opponent's Pokémon.

Backfire

Put 2 Fire Energy attached to this Pokémon into your hand.

Massive Heat Wave-GX

Discard an Energy from each of your opponent's Pokémon. (You can't use more than 1 GX attack in a game.)

When your Pokémon-GX is Knocked Out, your opponent takes 2 Prize cards.