Foul Presence

Most -1/-1 effects fire once and walk away: a single shrink, a single death. This Aura turns its host into a renewable shrink engine instead. The enchanted creature pays its tax up front, eating a -1/-1 the moment the Aura lands, but in exchange it gains a tap ability that pings any creature for -1/-1 until end of turn, killing one-toughness pests outright and clipping anything else a point at a time. The catch buried in that wording is what defines how you use it: the penalty wears off at cleanup rather than sticking, so you cannot grind a 2/2 down across two separate turns. Each activation is a one-shot for the turn it fires, which pushes the card toward instant-speed value rather than slow accumulation. That reframes it as a combat valve more than a removal faucet: tap in response to an attack to drop an attacker below lethal, shrink a blocker out of a favorable trade, or finish a creature already softened by other damage that same turn. The price for all this is the price every Aura pays: two-for-one exposure on the front end, summoning-sickness lag before the engine comes online, and a host that has to live long enough to start tapping. Color-pie-wise it is black doing what black does, attrition by inches rather than a clean single answer, here wrapped around a creature that keeps offering the option as long as it survives.