Fight to the Death

Combat tricks usually reward the player who declares attacks; this one punishes everyone who has stepped into the combat step. The card is a punishment for engagement: only creatures that have entered combat as blockers or as blocked attackers die, which means it does nothing to a board sitting still and everything to a board that committed. That timing window is the whole strategic axis. The caster does not pick targets: "blocking" and "blocked" are statuses the game assigns during the declare blockers step, and the spell sweeps all of them. So the trick rewards the player who controls when and how the combat math resolves, not who reads the board after the fact. A symmetrical one-for-one clash leaves you trading your committed attackers for their committed blockers; the lopsided wins come from steering the assignment beforehand, most dramatically with a Lure-style effect that forces a crowd of blockers onto a single attacker before this clears the lot. The Boros pairing is exact: red supplies the aggression that forces the combat, white supplies the willingness to clear the board wholesale, and the symmetry is meant to be broken by board position rather than by a clause on the card. Walls left at home, creatures that never attacked, anything outside the combat all survive. It is a fight spell scaled up to the entire combat step, with the catch that you are usually feeding it some of your own creatures to take more of theirs.