Brock's Pewter City Gym (Hidden Fates 54/68)

Brock's Pewter City Gym

Onix-GX (both yours and your opponent's) take 40 less damage from the opponent's attacks (after applying Weakness and Resistance).

Card rule

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.