Keldon Necropolis

A repeatable damage source that lives on a land instead of a creature, which is precisely the trait that lets it survive where its creature-shaped cousins die. The first mode taps for colorless like any utility piece; the second pays four and red, eats a creature, and pings any target for two. That cost is deliberately punishing on three fronts: the generic mana, the red pip, and a body you have to feed the engine each time it fires. What you buy with that price is durability. A creature with a comparable activated ping folds to every sweeper, every spot-removal spell, every edict; a land that does the same work demands land destruction specifically, and few decks are equipped to answer a single source that way. The creature tax marries it naturally to sacrifice lines that already generate spare fodder, since each shot wants a body you were willing to lose. As a closer it converts a stalled board into reach, turning creatures that have stopped attacking into two-point bursts aimed wherever they matter. The legendary tag is the only brake on stacking copies, a relic of early-era design philosophy that leaned on the legend rule to balance utility lands rather than tightening activation costs. Note that it can never operate from a truly empty board: the sacrifice clause is part of the cost, so the engine is only live when you have a creature to spend.