Bombard

Four damage at instant speed for three mana is a clean, deliberately unglamorous design: the number is the whole calculus. Three damage has long been the genre's ceiling for a one-card creature answer, and pushing to four catches the four-toughness midrange bodies that three would bounce off. That extra point is paid for on the other side of the ledger. It cannot point at a player, cannot point at a planeswalker, and the heavier cost keeps it from competing with the truly cheap burn that doubles as reach to the face. Where a one- or two-mana removal spell trades up on tempo, this one asks you to spend the turn on a clean kill and nothing else. What it offers in exchange is reliability at instant speed: hold it through the draw step, fire it on the attack, and ambush the thing your opponent overcommitted into. This is the workhorse end of red removal, the spell whose entire reason to exist is answering a problem creature without any conditions to satisfy: no death trigger to arrange, no spectacle to enable, no life to pay. There is no clever wrinkle to chase, just a price set high enough that the four damage never has to be apologized for.