Pyroblast

The entire card hinges on one question: how much blue is in the room? For a single red mana it counters the spell or kills the permanent that would otherwise cost a full removal slot or a counterspell of its own, a rate so cheap an aggressive deck can leave it up almost incidentally. The qualifier is total. Pointed at anything nonblue the card does nothing; there is no flexible fallback, no half-trade to fall back on. That binary buys the price, and the narrowness is exactly what it pays for. The subtlety lives in the targeting. The oracle text lets it point at any spell or permanent and checks the blue clause only on resolution, which means it can legally target a nonblue spell, accomplish nothing, and still count as a spell cast and a target chosen. That distinction separates it from Red Elemental Blast, which can only target blue in the first place, and it matters wherever a red spell sitting on the stack is itself the payoff (magecraft, prowess, storm). Instant speed is the half that matters most: the counter mode only exists during the window while a blue spell waits to resolve, so the card has to be cheap enough to hold on a hunch and answer the threat the instant it appears.