Retaliate

Most board wipes ask you to choose a moment: clear the field now and absorb the damage, or hold and hope. This one inverts the question by making the attack itself the condition. Anything that dealt damage to you this turn dies, and nothing else does, so the spell rewards letting the swing land before you answer it. That is a defensive design with a vengeful temperament: the wider the alpha strike, the more comprehensive the sweep, and the creatures left standing are precisely the ones that never landed a hit. Because it destroys without targeting, it also slides past hexproof and shroud, killing attackers a conventional removal spell could not touch. Against a single attacker it is a four-mana sweep with a strange precondition; against a committed assault it is a one-sided wrath the opponent built for you. The instant speed does the heavy lifting, letting you wait through the entire combat step, take the hits, and resolve once the damage is locked in. The catch is the obvious one: an opponent who reads the open white mana simply declines to attack, and the card sits dead in hand. This is a punisher effect, the kind that turns the opponent's aggression into the condition rather than answering threats on your own terms, the deterrent white reaches for when it wants something that costs nothing until provoked. The asymmetry only exists if someone walks into it.