Forretress

It is encased in a steel shell. Its peering eyes are all that can be seen of its mysterious innards.

Ability — Thorn Tempest: When you play this Pokémon from your hand to evolve 1 of your Pokémon, you may put 1 damage counter on each of your opponent's Pokémon.

Iron Crash (20+): This attack does 20 more damage for each Colorless in your opponent's Active Pokémon's Retreat Cost.