Gravkill

Exile at instant speed has always been black's exception rather than its rule: the color's identity runs through destruction, sacrifice, and reanimation, all of which leave a corpse in the yard for recursion decks to mine. What this spell buys for its four mana is the clause black almost never gets to write: permanent removal with no death trigger, no graveyard to loot back from, and no regeneration or indestructibility to slip the net. The premium over black's cheaper destroy-effects is the tax for that finality, and it is paid at instant speed, which turns the spell into a clean answer to a creature or Spacecraft that resolves at the wrong moment. Just as telling is the reach into Spacecraft, a permanent type black has no other native way to interact with cleanly; folding it into the same instant that handles creatures means the color does not need a separate artifact-hate slot to keep pace. Structurally this is the black analog to the white and blue exile-removal that has anchored control shells for years, priced up rather than restricted, and handed to the color that most needs a way to make a threat stay gone.