Once per turn: You can send 1 "Spellbook" Spell Card from your Deck to the Graveyard. During the End Phase of the turn this card activated this effect: You can Tribute this card; Special Summon 1 Level 5 or higher DARK Spellcaster-Type monster from your Deck. You must have 5 or more "Spellbook" Spell Cards with different names in your Graveyard to activate and to resolve this effect.