Each Pokemon in play that has Delta Species on its card (both yours and your opponent's) has no Weakness and can't use any Poke-Powers.

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.

Each Pokémon in play that has δ on its card (both yours and your opponent's) has no Weakness and can't use any Poké-Powers.