Quash

Counterspells stop a spell once; this one stops a spell forever. The counter is just the entry fee. What it pays for is the search that follows: every copy of that named spell, anywhere in the controller's graveyard, hand, and library, hunted down and exiled. Counter a Lightning Bolt with Counterspell and the other three are still in the deck. Counter it here and those three cease to exist. The design idea is surgical rather than reactive: it treats a deck's redundancy as the real threat and removes the redundancy, not just the instance. That makes it a tool aimed at a specific kind of opponent, the one whose plan leans on resolving a particular spell, and it does nothing extra against a deck that wins fifteen different ways. Two limiters keep the effect honest. The first is the naming clause: it only reaches cards sharing the countered spell's name, so it can never become a generic answer to a whole color or card type. The second is the target restriction: it counters only instants and sorceries, which walls it off from creatures, planeswalkers, and artifacts entirely and narrows its window to the spell-based decks it was built to dismantle. The cost reflects that narrowness. Four mana for a counter that can only reach half the spells in the game is a premium rate, one that pays off solely when you know exactly which spell wins the game and decide that deleting the whole playset is worth it.