Choose 1 of your opponent's Benched Pokémon. This attack does 20 damage to that Pokémon. (Don't apply Weakness and Resistance for Benched Pokémon). Flip a coin. If heads, prevent all effects of an attack, including damage, done to Giratina during your opponent's next turn.
Does 50 damage plus 10 damage for each damage counter on the Defending Pokémon.