During your Main Phase: You can activate this effect; this card in your hand becomes revealed until the end of your opponent s turn. 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 (except during the Damage Step): You can Special Summon this card from your hand, then, if you activated this effect while this card was revealed, you can reveal and Set 1 Spell Trap directly from your Deck, but banish it during the End Phase of the next turn. You can only use 1 Lord of the Heavenly Prison effect per turn, and only once that turn.