Theorealize Ephemeral Lull

(This card is always treated as a "Power Patron" card.)
Banish 1 "Medius" monster from your hand or face-up field; banish as many monsters on the field as possible that were Special Summoned from the Extra Deck, then you can Special Summon 1 "Artmage" monster from your GY. If you have 3 or more different Monster Types on your field: You can banish this card from your GY; Special Summon 1 of your banished "Medius" monsters. You can only use each effect of "Theorealize Ephemeral Lull" once per turn.