Allure of the Unknown 
Sorcery
Reveal the top six cards of your library. An opponent exiles a nonland card from among them, then you put the rest into your hand. That opponent may cast the exiled card without paying its mana cost.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL