Smite

The combat trick that punishes the attacker for swinging into a wall. Most one-mana white answers of its era hedged: pump effects to win a fight, or cheap exile that asked nothing of the board state. This narrows the targeting clause to a single condition (the creature must already be blocked) and pays for that restriction with unconditional destruction at a price no fight spell can match. The restriction is what gives the card its shape: you cannot fire it proactively, so it lives entirely inside the combat step, after blocks are declared. You let an attacker come in, throw a blocker in front of it, and then Smite the thing your blocker is now staring down. The window is the whole appeal. The attacker commits to the assault, the defender declares a block, the "blocked" status latches on, and from there the card resolves regardless of toughness or whatever pump the attacker's controller was holding to win the fight. The one caveat is that "destroy" is exactly that: regeneration and indestructible both walk away clean, which is the standard ceiling on any destruction effect and the reason it is not a universal answer. Smite is therefore a defensive tempo tool dressed as removal: it does nothing against a board sitting still, and everything against an opponent who overcommits to the attack. The cost of that conditionality is total dead-card risk against passive decks, which is the friction a one-mana destroy effect should carry.