Championship Arena is a Trainer card from the Nintendo Black Star Promos expansion of the Pokémon Trading Card Game (card #28, Promo).
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.
At the end of each player's turn, if that player has 8 or more cards in his or her hand, that player discards a number of cards until that player has 7 cards left in his or her hand.
Illustrated by Ryo Ueda