Altar of Shadows

Seven mana for an artifact that, the moment it resolves, does nothing but sit there and accrue. That is the gamble at the heart of this design: a mana engine that ramps black backward, paying out only what you have already invested in it. The first activation costs seven to destroy a creature and seed a single charge counter; from then on each removal click adds another counter, and at the beginning of your first main phase those counters start printing black mana. The two halves are deliberately welded together. Spend the seven on removal and you grow the mana base; grow the mana base and you can afford to spend the seven again. It is a snowball that only rolls once you have shoved it uphill, and the artifact's vulnerability in the gap between cast and first payout is the price an era of cheap artifact ramp exacted for an effect this open-ended. The destruction is unconditional and repeatable, the mana uncapped; the only real ceiling is how long the game lasts and how much you sank in before the counters began compounding. As a piece of slow, top-heavy black artifact technology it reads less like a removal spell and more like a long-game thesis: that if you survive to the back half, an engine that both kills threats and fuels itself will eventually outpace any amount of incremental pressure.