As long as Gengar is your Active PokÃ©mon, if any of your opponent's PokÃ©mon would be Knocked Out, put that PokÃ©mon in the Lost Zone instead of discarding it. (Discard all cards attached to that PokÃ©mon.)
Hurl into Darkness
Look at your opponent's hand and choose a number of PokÃ©mon you find there up to the number of Psychic Energy attached to Gengar. Put the PokÃ©mon you chose in the Lost Zone.
Put 4 damage counters on your opponent's PokÃ©mon in any way you like.