The Stadium card serves as an easy way to get the decks centerpiece Pokmon (or in the case of the Charizard ex deck, perhaps one of its key supporting Pokmon) in play while circumventing the Item-locking effect of the Itchy Pollen attack of the Budew card from Terastal Festival ex [SV8a]
"Pokmon TCG" and "Pokmon TCG Pocket" UT Collection to Be Released on August 11
If you want to go the extra mile to ensure authenticity, you can also ask the seller to weigh the card, booster bundle, booster box, or pack theyre selling and timestamp that before sending it to you
Keep working on your deck, and aim for a good balance of bombs, removal, card advantage, and mana curve
If things start spiraling out of control, theres always Vorpal SwordVorpal Sword or Revel in RichesRevel in Riches to end the game fairly quickly, or a massive ExsanguinateExsanguinate powered by a plethora of Treasure tokens