Thrull Parasite

Most extort creatures are content to sit and drain: the keyword turns spellcasting into a slow life-swing, and the body is incidental. This one carries a second job worth more attention than the drain plan. The tap ability strips a counter off any nonland permanent for two life, and the breadth of "any counter" is doing the heavy lifting. A loyalty counter is a counter. So is a +1/+1, a charge counter on an artifact, a quest counter, a divinity counter, the lore counter ticking up a Saga. At one black mana it is a repeatable wrench: shrink a creature it can't kill outright, push back a planeswalker's loyalty before it ultimates, stall a Saga short of its final chapter, or dismantle whatever counter-based engine an opponent is leaning on, one activation per turn. The catch is the word "permanent": the counter has to be on something already on the battlefield, so a suspended card winding down in exile is out of reach, as is anything else parked off-board. The life payment is the throttle, since two life a turn against a developing board adds up, and the removal rate is slow by design. What you are paying for is the option to interact with an entire category of permanents that most cheap black creatures simply ignore, packaged onto a one-drop that chips through extort while it waits for a target.