Unown [D].

Pokémon Power[Darkness]

Whenever a Darkness Pokémon damages 1 of your Pokémon, reduce that damage by 30 (after applying Weakness and Resistance). This power stops working if you have more than 1 Unown [D] in play. (This power works even if Unown [D] is Asleep, Confused, or Paralyzed.)