Boompile

Tap it, and the table holds its breath. Half the time the coin lands wrong and the artifact just sits there, wasting your turn and telling everyone exactly what you were trying to do; the other half it clears every nonland permanent off the table, yours included. That fifty-fifty is the whole exchange: the four mana buys nothing but the recurring right to gamble, and unlike a Wrath of God you cannot promise the reset, only threaten it. There is no partial outcome, no fizzle into a smaller effect, no scaling. Everything nonland dies or nothing does. This puts it in the old line of randomized symmetrical destruction, the sweepers that hand you repeatable board control but tax the guarantee out of it, and it commits harder to the coin than most: no hedge, no consolation, just the binary. The strategic weight lives less in the flips it wins than in the flips it might win. An opponent can crack the rock between activations or hold up an answer, but as long as it survives untapped, everyone deploys threats knowing the reset could arrive at any moment. It is a card for the player who wants the board to feel unstable, where the mere presence of the coin waiting to be flipped changes how the game is played long before it ever destroys anything.