Aerial Volley

The targeting clause is the whole pricing argument. A one-mana instant that dealt three damage to anything would be a maindeck staple in any era; restricting it to fliers and only fliers turns it into a reactive trump card that is blank against a ground assault. What you buy for the green mana is flexibility within that narrow lane: kill one large evasive threat, or fan the damage across a swarm of one- and two-toughness fliers at the moment they declare as attackers. Green has long leaned on this kind of color-pie patch, reaching toward Plummet and Hurricane to cover a gap it is otherwise built to be weak against, but those answer fliers at sorcery speed or hit your own life total in the bargain. This trades raw reach for precision and the instant-speed window, letting you hold up the trick and decide after attackers commit. It lives or dies on what is across the table, which is exactly the point of a tightly walled removal spell: cheap and devastating against the one thing it was built to punish, useless against everything else.