Doom Foretold

A symmetrical tax that isn't symmetrical: both players feel the upkeep tribute, but only its controller collects when the well runs dry. The mechanism is a stacked ultimatum. Each turn, every player must feed the enchantment a nonland, nontoken permanent, and the moment someone runs out of eligible fodder, they pay the whole penalty package at once (discard, life loss, and a cascade of value handed to the enchantment's owner) before Doom Foretold sacrifices itself. That self-sacrifice is the pivot the whole card is built around. Because the enchantment eats itself the instant it triggers its payoff, it becomes a permanent your opponent is desperate to strand you on, and one you're happy to keep alive with your own worst cards. The tension lives entirely in the queue. The tokens and Treasures that let most attrition shells absorb pressure are precisely the permanents Doom Foretold refuses: you cannot chum the water with a Knight the enchantment itself makes. So the supply that matters is a curated bench of cheap, disposable nonland permanents (a spent Signet, an enchantment you no longer need, a creature that already did its job) that you'd rather sacrifice than any real threat. It rewards a deckbuilding discipline most attrition tools don't demand: not raw card advantage, but a stockpile of things you're glad to lose, weaponizing an opponent's own reluctance to part with their best permanents against them.