Pyxis of Pandemonium

Symmetry as a gameplay engine, played out across an entire table. Every activation feeds the same hopper for all players at once, building a face-down stockpile no one can read, and the payoff dumps the whole thing onto the battlefield simultaneously: lands, creatures, artifacts, enchantments, planeswalkers, whatever the random exile happened to bury. What complicates the design is that it promises a board-state explosion but hands the same explosion to everyone, so its value depends entirely on who is positioned to exploit a sudden flood of permanents and who drowns in it. The seven-mana plus tap plus sacrifice cost on the back half is a real commitment, and the gap between the cheap tapper and the expensive detonator is the whole game: you spend turns charging an artifact whose output you cannot see and cannot aim, then pay a premium to flip the coin for the table. It rewards builds that can convert raw permanents into immediate advantage faster than opponents, and punishes the player who triggers a payoff that gives a rival the missing piece. It belongs to the same symmetrical-engine tradition as Howling Mine or Temple Bell, but where those share cards, this shares a deferred, randomized board wipe-in-reverse that resolves all at once for everyone who owns something in the pile.