Ghostrick Skeleton

Cannot be Normal Summoned, unless you control a "Ghostrick" monster. Once per turn: You can change this card to face-down Defense Position. When this card is flipped face-up: Banish cards from the top of your opponent's Deck face-down, up to the number of "Ghostrick" monsters you control. You can only use this effect of "Ghostrick Skeleton" once per turn.