Mana Vortex

A symmetrical land-destruction engine with a built-in self-destruct, and one of the purest expressions of the early-design instinct to make a powerful effect "fair" by pointing it at everyone, including its caster. The cost is paid in lands, not just mana: the spell counters itself unless you sacrifice one on the way in, which means you start the bleed a turn ahead of the table. From there the board shrinks by one land per upkeep, every player feeding the engine from their own mana base, and the enchantment only immolates once there are no lands left on the battlefield at all (not when a single player hits zero, but when everyone does). The design logic is symmetry-as-tempo: the player who deploys it wants to be ahead on board or already committed to a non-land plan, so that mutual mana starvation costs the opponent more. It is the slow-motion cousin of Armageddon, trading the one-shot wipe for a grinding cumulative tax that the affected players administer to themselves. That self-policing structure is what kept the rate in check before the modern vocabulary of finality counters and exile clauses existed: the card cannot run forever, because it eats its own fuel and the rest of the table's besides. The symmetry is rigged at the seams, and the whole thing is engineered to consume itself before the game can fully lock up.