During your opponent's Battle Phase: Choose 2 Spell/Trap Cards from your Deck and 1 monster in your Main Monster Zone. Special Summon them as Normal Monsters (ATK 0/DEF 0) in face-down Defense Position, Set the chosen monster if it is face-up, and shuffle them on the field. The 2 cards chosen from your Deck are destroyed at the end of the Battle Phase, and cannot remain on the field except during this Battle Phase.