Hex Parasite

Counter removal is a narrow effect, the kind of answer most decks never want and a few decks cannot function without, and this one packages it into a recurring engine rather than a one-shot. The activation strips counters off any permanent and converts each into a temporary +1/+0, so the same card that drains a planeswalker's loyalty before it ultimates, or empties a charge counter store before it crosses a threshold, also threatens to attack for real damage the same turn it cashes those counters in. The Phyrexian cost is what lets it function in any shell: the colored requirement folds into a life payment, so green, white, or even colorless piles with no access to black can still fire the ability. That reach is paid for at the body, a 1/1 that does nothing until you spend mana on it, and the buff evaporates at end of turn, so the combat math has to resolve in the same turn you pull the counters. The sharpest interaction runs sideways into the -1/-1 counter rules: a Persist creature returns only if it has no -1/-1 counter on it when it dies, so removing that counter while the creature is on the battlefield resets it to come back again, while leaving it alone is what finally ends the loop. A surgical answer to problems most of the card pool cannot touch, built for the pile that has named its target in advance.