Outnumber

The deal is simple and the catch is brutal: a one-mana removal spell whose entire output is the board state you bring to it. With an empty side it does nothing, kills nothing, sits dead in hand; the moment you've committed a wide board it scales past anything a single burn spell could reach for the price. So the card inverts the usual logic of removal. It punishes you in exactly the matchups where you most want removal (the grindy, creature-light games where you're behind on the board) and overpays you in the ones where you'd rather just attack. What it wants is a deck already winning the numbers game, handing that deck a cheap way to clear the one blocker or the one threat between it and lethal, which is a strange thing for a removal spell to ask. Token-makers and go-wide aggression are the natural homes, where the count is reliably high and the mana cost stays trivial. Read against the red removal canon, it sits at the far end from the unconditional answers: where Lightning Bolt asks nothing of your board and always trades up, this asks everything of your board and trades up only when you needed it least. The instant speed matters more than the rate suggests, letting you ambush an attacker mid-combat or hold the spell up while you keep building width, but the floor never moves: it is exactly as good as you are ahead.