You can reveal 1 Ritual Monster in your hand: Special Summon this card from your hand. You can target 1 "Libromancer" card in your GY, except "Libromancer Agent"; add it to your hand, then if you added a Spell/Trap by this effect, place 1 card from your hand on the bottom of the Deck. You can only use each effect of "Libromancer Agent" once per turn.