Kill Shot

Destruction that only touches a creature already swinging is one of white's oldest balancing levers: a way to print broad removal without printing it proactively. The attacking-only clause is the whole tax. It cannot break up a combo, kill a mana dork before it taps, or clear a blocker to push damage through. It waits for the declare-attackers step and punishes the swing, which makes it a defensive answer rather than a proactive one: it rewards the player holding open mana behind an empty board and penalizes the aggressor for over-committing to combat. This is reactive-control logic, not tempo; the deck that wants this effect is the one happy to sit back and let the opponent walk into it, not the one trying to clear the way for its own attackers. The rate is not a bargain: unconditional white removal often costs the same, and pricing reactive insurance here reflects how little the restriction actually saves designers. What it buys instead is reach. Subject to the usual targeting rules (a hexproof attacker shrugs it off, since the spell must choose a legal target), it answers nearly anything that swings regardless of size or color, at instant speed, off untapped mana. The lineage runs through every white effect that asks the opponent to attack into open mana, the same window logic that lets ambush blockers and combat-only kill spells undercut the cost of their unconditional cousins.