Magistus Invocation
Fusion Summon 1 Fusion Monster from your Extra Deck, using monsters from your hand or field as material, including a Spellcaster monster. If Summoning a "Magistus" Fusion Monster this way, you can also use monsters in your Spell & Trap Zones that are equipped to a "Magistus" monster. You can only activate 1 "Magistus Invocation" per turn.