Swift Reckoning

The "destroy target tapped creature" template has a long lineage of being a sorcery's worth of removal at instant value: the restriction to tapped creatures is the price white pays for a cheap, color-appropriate kill spell, given how the color has historically struggled to answer creatures one-for-one. What this design adds is a conditional unlock, and the two halves point the same direction. The tapped clause is itself a tempo lever, since the most reliable way to find a tapped creature is to let it swing at you, which pulls the spell toward a reactive, combat-step posture. Spell mastery then rewards a graveyard stocked with instants and sorceries by granting flash, so the kill can wait for the attacker to commit, when the window is widest. This is a removal spell built to punish an attack rather than preempt it, and it is most natural in a deck already churning through cheap spells, where the two-card graveyard threshold arrives by midgame as a matter of course rather than a deckbuilding tax. Read straight off the card it is a modest answer, but the spell-mastery turn quietly converts a sorcery-speed liability into an ambush, and the design rewards the player who has done the work of filling a graveyard before the question of casting it ever comes up.