Incite Rebellion

The damage scaling is the trap: each player takes a hit equal to their own board size, and so does every creature they control. The player flooding the board to win the game is precisely the one who burns down their own army and most of their life total when this resolves. That self-inflicting symmetry is the whole design. A go-wide deck running thirty creatures hands itself thirty damage; a control player sitting on an empty board takes nothing. As a board wipe it reads upside-down from the usual logic, where the player most invested in creatures is the one a wrath punishes hardest, except here the punishment lands on their face as well as their battlefield. The intended pilot is the deck with few or no creatures of its own: token-light, artifact-heavy, or a spellslinger build that would rather close the game by knocking three opponents to single-digit life than by attacking. It is a symmetrical effect that asks you to build asymmetrically, and the reward for doing so is one of the rare sweepers that doubles as a finisher. Six mana and the sorcery restriction rule out any reactive use; you cast this on your turn, into a developed multiplayer table, and watch everyone else pay for committing to the board you declined to build.