Aquapolis · #138
Undersea Ruins is a Trainer card from the Aquapolis expansion of the Pokémon Trading Card Game (card #138, Uncommon).
This card stays in play when you play it. Discard this card if another Stadium card comes into play.
Once during each player's turn (before attacking), that player may flip a coin. If heads, that player chooses 1 of his or her Evolved Pokémon in play and discards the top Evolution card from that Pokémon, devolving it.
Illustrated by Midori Harada