Keeper of Dragon Magic

If this card is Normal or Special Summoned: You can discard 1 card; add 1 "Polymerization" Normal Spell or "Fusion" Normal Spell from your Deck to your hand. You can reveal 1 Fusion Monster in your Extra Deck; Special Summon 1 of the Fusion Materials whose name is specifically listed on that card from your GY in face-down Defense Position. You can only use each effect of "Keeper of Dragonic Magic" once per turn. You cannot Special Summon monsters from the Extra Deck, except Fusion Monsters, the turn you activate either of this card's effects.