Goblin Freefall Squad - Phantom Nightmare

If this card is Special Summoned from the hand in Attack Position: You can target 1 face-up Effect Monster your opponent controls; change this card to Defense Position, also negate the effects of that monster while this monster is in face-up Defense Position. If a monster(s) is Special Summoned to your opponent's field, while this card is in your GY (except during the Damage Step): You can discard 1 card; add this card to your hand. You can only use each effect of "Goblin Freefall Squad" once per turn.