Burst Lightning

The interesting trick here is that the mana cost never changes: it is always one red mana to cast, and the kicker rides on top as a late-game option rather than a tax you pay to get in the door. That structure makes the card a single answer that scales with the game state. Early, when two damage clears a mana dork or a one-toughness threat, you pay the minimum and move on. Later, when you have mana to spare and need to reach a four-toughness creature or push the last points to a face, the same card in hand becomes a four-damage spell without your ever having drawn a different card. Designers reach for kicker precisely when they want a removal spell to stay relevant across the arc of a game without inflating its floor: the floor here is a clean, cheap, instant-speed two damage, and the ceiling is paid for only on the turns you can afford it. The "any target" clause is doing quiet work too, letting the kicked mode function as a reach finisher rather than strictly creature removal. It is a study in how a single optional cost can collapse two cards (a cheap early interaction spell and an expensive late burn spell) into one slot, and the reason it keeps getting reprinted is that the math on that trade has never stopped being favorable.