Tombstone Stairwell

A symmetry engine built on a graveyard the whole table is feeding. The Zombie production scales off creature cards in every player's graveyard, not just yours, which turns this from a personal army into a board-state referendum: whoever has buried the most bodies suddenly commands the largest horde, and the count refreshes every upkeep. The World designation matters as much as the text. Only one Tombstone Stairwell can be in play at once, so a second copy supplants the first rather than stacking, a use of the World rule to keep a permanent that would otherwise compound out of control to a single instance. Two restrictions keep the rate honest. Cumulative upkeep means the army gets more expensive every turn you keep it, so the engine has a built-in clock you pay in mana. And the end-step wipe (plus the destroy-all trigger when the enchantment leaves) means the Tombspawn are creatures of the upkeep only: they swing or block, then evaporate before they can be permanently leveraged. The haste exists precisely because the tokens never survive to a second turn, so they have to be useful the moment they appear. The design is a closed loop of give-and-take: free bodies, paid back with escalating mana and erased every end step, all of it gated behind a permanent that allows no duplicates. It reads like a token generator; it behaves like a turn-by-turn lease on an army you can never quite own.