Bloodfire Kavu

A 2/2 for four that walks onto the battlefield doing nothing useful is a deliberate trade-off here: the body is a fuse, not a threat. Pay one more red and feed the Kavu to the engine and you get a board-clearing pulse, two damage to every creature. That puts it in the same family of red sweepers built on sacrifice rather than on a sorcery card slot: a Pestilence in miniature, a single-shot Earthquake you can hold in play until the board is right. The asymmetry it cares about is toughness. Three-toughness creatures survive, so the card is a wrath aimed squarely at the swarm that red was built to punish: tokens, weenie aggro, mana dorks, the wide-and-fragile boards that two damage to each creature erases in one activation. The friction is that the sweep is one-shot and self-immolating, so you are trading a permanent for a moment; you commit the Kavu to the battlefield as a clock, then cash it in when the math favors you. It also reads as a finisher in a pinch, since two damage to each creature catches your opponent's blockers as readily as their offense. A clean, honest piece of Apocalypse-era red design: the sweeper that asks you to pay for it twice, once in mana up front and once in the creature you give back.