Flip a coin. If heads, prevent all damage done to Cloyster by attacks during your opponent's next turn.
Flip 4 coins. For each heads, choose an opponent's PokÃ©mon in play and this attack does 20 damage to those PokÃ©mon. (You may choose the same PokÃ©mon more than once.) (Don't apply Weakness and Resistance for Benched PokÃ©mon.)