pokemon fighting energy cards » Rocky (Holo) holofoil pattern or surface detail) Strong Energy | XY—Furious Fists

Interestingly, a former WotC employee chimed in about this card

Some were originally pulled from booster packs, while rare Japanese promo versions were only awarded through the Pokmon Players Club

The collectible features a stunning artwork by KIYOTAKA OSHIYAMA, who illustrated the Kanto Fire-type locked into a fierce battle with Mewtwo

Sultai (Blue/Black/Green) The Mimeoplasm gives you access to green, black, and blue, and comes equipped with built-in graveyard removal, allowing you to exile two cards from opponents' graveyards to power it up

And you get to choose which side of the card you want to play

Two mana on an opening turn can allow a player to do all kinds of things that could start the ruination of their opponent