You need both Darkrai & Cresselia cards in order to play. Once you have both cards, place both on your Bench
Choose 2 Energy attached to Darkrai & Cresselia and put them in the Lost Zone. If any of your opponent's Pokémon would be Knocked Out by damage from this attack, put that Pokémon and all cards attached to it in the Lost Zone instead of discarding it.
Move as many damage counters on your opponent's Pokémon as you like to any of your opponent's other Pokémon in any way you like.