• Piercing Claw

  30x

  This attack does 30 damage for each damage counter on your opponent's Active Pokémon.

• Direct Arrow

  This attack does 80 damage to 1 of your opponent's Pokémon.(Don't apply Weakness and Resistance for Benched Pokémon.)

The air stored inside the rachises of Decidueye's feathers insulates the Pokémon against Hisui's extreme cold. This is firm proof that evolution can be influenced by environment.