Flame Javelin

Four damage to anything at instant speed is the headline, and red almost never gets it without a string attached: a death trigger to enable, a sorcery-speed clamp, a life payment, a clause that fizzles against the wrong target. This one is unconditional. The trick is that its printed cost reads like six but rarely is. The symbols let the card size its color requirement to your manabase rather than forcing the manabase to bend around it: a deck flush with red fires it for three red mana, a deck splashing red off scattered sources pays with whatever it has lying around, and the worst case (paying full generic) is one a dedicated red deck almost never sees. That is the design's whole argument. Hybrid mana had mostly been used to soften color commitments on smaller effects; pushing it onto a four-damage burn spell let designers print a number red usually has to pay a downside for and charge for it in color devotion instead. The result is burn that reads as a luxury and plays as a staple. The four-damage band is what has kept it relevant: it answers a wider span of creatures than three does, and it closes games a turn or two earlier, with no rider to set up and no target it cannot hit.