Divide by Zero 
Instant
Return target spell or permanent with mana value 1 or greater to its owner's hand. Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL