Pith Driller

Strip the cost down to its colorless component and what you have is a 2/4 that shrinks something on the way in, ordinary work plenty of black creatures have done before. But the clause means this never needs black mana at all: pay four generic and two life, and the -1/-1 counter lands in any deck that can muster the mana and is willing to bleed for the rest. That is the trick at the heart of Phyrexian mana. It quietly converts a color-pie effect into something a colorless or off-color mana base can run, even though the symbol still pins the card's color identity to black in the formats that track it. The counter is permanent reduction rather than a temporary debuff, which matters against toughness-based blockers and against the two graveyard-recursion keywords from the same era: a -1/-1 counter stops a persist creature from coming back at all (it dies already carrying one), and it can preemptively cancel out the +1/+1 counter undying would leave behind. The artifact type means the card answers a question and then lingers as a permanent that other artifact synergies can use. The price of all that flexibility is the two life and the slow speed: a small, honest tax for an effect that would otherwise demand a black source, and a clean illustration of how Phyrexian mana smuggles one color's identity into any deck willing to pay in flesh.