Clear, Fair Magic [Un-Known Event Playtest Cards]

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact, enchantment, token, emblem, day/night tracker, monarch, initiative, dungeon, city's blessing, Attraction, Contraption, plane, scheme, vanguard, bounty, conspiracy, elite creature, or Magic: The Gathering Online avatar.