Iron Cage (Ultra Rare)

When this card is activated: Send 1 monster you control to the GY, or if "Golden Castle of Stromberg" is in a Field Zone, you can send 1 monster your opponent controls to the GY, instead. Once per turn, during your Standby Phase: You can target the monster that was sent to the GY by this card's effect, destroy this card, and if you do, Special Summon that monster to your field. You can only activate 1 "Iron Cage" per turn.