Janine's Secret Art (Mirror Foil) (166/187) [SV8a: Terastal Fest ex]

Choose up to 2 of your Darkness Pokémon. For each of those Pokémon, search your deck for a Basic Darkness Energy card and attach it to that Pokémon. Then, shuffle your deck. If you attached Energy to your Active Pokémon in this way, it is now Poisoned.