Cleaving Skyrider

Cast unkicked, this is a plain evasive body you flash in to ambush an attacker or apply reactive pressure. The red kicker rewrites the spell: pay the surcharge and the enter trigger deals X damage to any target, where X counts the attacking creatures on the battlefield. The quiet trick in the design is that "attacking creatures" belongs to whoever declared the attack, not to you. Flash the kicked version in mid-combat during the opponent's swing and their wide alpha strike becomes the fuel for your removal: five attackers become five damage pointed at a planeswalker, a player, or the biggest thing coming your way. On offense the trigger scales off your own board instead, so the card operates from either side of the combat step. Splitting the cost across two colors is what keeps the base body cheap: white alone gets you a clean three-mana flier, and access to red converts it into a Boros finisher without editing a word of the top line. The tension is real but it is not the offense-defense split it first appears, since a big attack is a big attack no matter whose it is. It sits between patience and payoff: the flash flier wants you cheap and reactive, while the kicked mode wants a crowded battlefield to point its single burst at.