Yawgmoth's Agenda

A graveyard that works in only one direction, paid for by a tax on your whole turn. The third clause is the trap most readers miss: nothing you own ever reaches the graveyard while this is out, because everything is exiled instead. So the recursion in the second line feeds on whatever was already in your yard when the enchantment resolved. That sets a hard ceiling: the cards you replay never return to the graveyard, since they'd be exiled instead, so each is a strict one-shot, and the well never refills. This is a closer for a deck that has already loaded its yard and now wants to spend it, not an engine that refuels itself. The one-spell-per-turn restriction is the second brake, ensuring a free graveyard does not become a chain of casts: one spell per turn, chosen with care. The flavor lands exactly where the rate does. Yawgmoth's whole conceit on Dominaria was a power that wins by consuming its own resources, and the card models that literally: it converts your graveyard from a renewable pool into a depleting one, trading the option of a long game for a methodical, guaranteed replay of your best cards. It rewards a deck built to mill or discard into a stocked yard, then grind an opponent down one deliberate spell at a time, knowing the supply is finite from the turn it resolves.