As long as Walrein ex is your Active Pokémon, put 1 damage count on each Active Pokémon (both yours and your opponent's) between turns, excluding Pokémon.

Choose 1 of your opponent's Pokémon. This attack does 40 damage to that Pokémon. (Don't apply Weakness and Resistance for Benched Pokémon.)

When Pokémon-ex has been Knocked Out, your opponent takes 2 Prize cards.