Counterbore

Most counterspells answer one copy of a card. This one answers the concept. The counter is the cheap part; the surgery that follows is the point, hunting every other copy of that spell across hand, library, and graveyard and exiling the lot before the shuffle. Against a singleton you have spent five mana on an oversized Cancel; against a deck leaning on four copies of a key card, you have removed the deck's reason to exist in a single resolution. That trade is the whole calculation. The effect extinguishes a name rather than an object, which puts it nearer to graveyard-and-deck-stripping attrition like Cranial Extraction than to ordinary permission, except it does its work on the stack instead of waiting for a sorcery window. The friction is the price. Five mana held up at instant speed to counter a single spell is a tempo loss most decks cannot afford, so the payoff only materializes against an opponent who has committed to redundancy. It rewards knowing what the table is built on: a value engine run as a four-of, a combo piece the deck cannot win without, a recurring threat the graveyard keeps handing back. Find that card, and Counterbore does not just stop a spell; it deletes a plan.