Steelix.

This attack does 10 damage to each of your opponent's Benched Pokémon. (Don't apply Weakness or Resistance for Benched Pokémon.) Then, flip a coin. If tails, this attack can't be used during your next turn.

Flip 2 coins. If both are heads, this attack does 50 damage plus 20 more damage. If both are tails, this attack does nothing. If 1 is heads and 1 is tails, this attack just does 50 damage.