Mausoleum Harpy

Ascend is the mechanic that lets a payoff wait patiently for a board state black attrition decks were already assembling: a wide field, sacrifice fodder, creatures cycling through the graveyard. The flying body evades blockers on its own, but the counter trigger sits inert until the city's blessing switches on, and then the death triggers start compounding, every other creature that dies feeding a flier that quickly outgrows what five mana usually purchases. The sequencing is the whole trick, not the raw numbers. Once you cross the ten-permanent threshold the blessing sticks: the harpy never re-checks the count, so it stops being a machine you have to keep enabling and becomes a standing engine that grows on every sacrifice no matter what happens to your board afterward. That one-way door is the quiet cleverness of bolting this mechanic onto this trigger. The entry cost is what balances the climb. You need the blessing before any of the deaths mean anything, and a deck that cannot reliably field ten permanents is left with a 3/3 flier whose best trick never fires, watching its creatures die for nothing. Built right, the climb is steep and irreversible, an evasive threat that converts a grindy trading game into a clock the instant the table starts swapping bodies.