Golduck δ

Choose 1 card from your opponent's hand without looking. Look at the card you chose. If that card is a Trainer card, this attack does 30 damage plus 30 more damage, and discard that card. If that card is not a Trainer card, return it to your opponent's hand.

As long as any Stadium card with Holon in its name is in play, your opponent can't play any Stadium cards from his or her hand.