Mishra's Self-Replicator

Every copy this makes is another 2/2 carrying the exact same trigger, and that recursion is the whole engine: once two or three replicators sit on the battlefield, a single historic cast forks into a stack of independent triggers, each offering its own copy for one mana, each new copy live for the next historic spell. Artifacts are themselves historic, so this creature partly feeds itself; point one artifact cast at a board of replicators and watch the count spiral. The optional per-body payment is the brake keeping the multiplication honest: nothing is free, and you are never forced to dump mana into a board you cannot protect. The five-mana price for a 2/2 is the tax on all of it, and it is a steep one. A body this small, whose only text is a trigger that does nothing until there is a historic spell to feed it, demands a deck dense enough in artifacts, legendaries, and Sagas to turn the crank before the arithmetic starts to matter. This is not a card that ends things the moment it arrives; it rewards an accumulated board and a long historic curve, the kind of design meant to make a synergy keyword feel like an archetype rather than a sticker glued onto individual cards.