Dragoniscience. Seems basically useless; you can cast any spells from hand for free these days by milling or discarding Omniscience and bringing it back on turn 3 or 4 with Abuelo’s Awakening.

Unlike Omniscience, this lets you free cast from zones other than your hand when combined with, say, red’s common “temporary draw” effects (“Exile the top N cards of your library. Until end of turn, you may play them.”)