Arc Lightning

Three damage for three mana is a poor rate against any single creature, and red has always had cheaper ways to throw three at one body. The markup buys you a dial: that three damage splits across one, two, or three targets however you assign it. Against a lone oversized threat it overpays; against a row of one-toughness attackers it works as a one-card sweep, killing three creatures before they swing, or splitting two-and-one to trade with a pair instead. The allocation is entirely yours, which is the whole appeal: a clean three-for-one when the opposing board is wide, or a focused burst into a single wall when it is not. The sorcery-speed restriction is the cost that keeps the breadth in check: you cannot hold it up against an alpha strike or a combat trick, so the split happens on your own turn with the full board visible, trading the instant-speed bluff for coverage. This is the divided-damage school of red removal, the one that swaps burst efficiency for reach: the answer you want when the problem is the number of creatures rather than the size of one. Its value scales directly with how cluttered the opposing side has gotten, which is precisely the board state that cheaper single-target burn handles worst.