Annihilate

The premium for the cantrip is exactly two mana and one color of friction. Black has always had clean, cheap removal that asks nothing in return: Doom Blade and its descendants kill at a fraction of this cost. What you are paying five for here is the back end, replacing the card you spent so the trade comes out even on resources. That math reads worse than it plays in a grindy, multicolor attrition war, where every removal spell is a one-for-one against a deck full of bombs and the player who runs out of cards first loses. The nonblack clause is the genre marker of its era, when black removal routinely declined to touch its own color; it functions more as a flavor tax than a real constraint, since the decks most likely to clog the board with must-kill threats are rarely mono-black. Annihilate is unglamorous by design: too expensive to anchor a removal suite on rate, too card-neutral to dismiss once a game stalls into topdecks and each draw step decides the match. It comes out of the school of black answers that buy attrition rather than tempo, built on the idea that a kill spell which replaces itself never costs you the long game even when it costs you the turn.