Rock/Effect. During your Main Phase: You can reveal this card in your hand (until the end of your opponent's turn), and if you do, while this card is revealed by this effect, Set cards on the field cannot be destroyed by card effects. If a Set Spell/Trap Card is activated: You can Special Summon this card from your hand, then, if this effect was activated while this card was revealed in the hand, you can Set 1 Spell/Trap directly from your Deck to your field, but banish it during the End Phase of the next turn. You can only use 1 "King of the Sky Prison" effect per turn, and only once that turn.