Holon Researcher (DS 95)
This card stays in play when you play it. Discard this card if another Stadium card comes into play. If another card with the same name is in play, you can't play this card.
"Discard a card from your hand. If you can't discard a card from your hand, you can't play this card. Search your deck for a Energy card or a Basic Pokémon (or Evolution card) that has δ on its card, show it to your opponent, and put it into your hand. Shuffle your deck afterward."