Unerring Sling

An anti-flying device dressed as a siege engine. The cost is deliberately heavy: three mana, the artifact's own tap, and the tap of a creature you would rather be attacking with, all to throw a single shot skyward. The payoff is narrow too, pointing only at attacking or blocking creatures with flying, which means the machine sits idle until the air war actually begins. That restriction is the whole design. Rather than printing a flat reach effect or a colorless ground-to-air bolt, this routes its damage through a creature's power, turning a beefy untapped body into ammunition against the one threat ground decks historically could not touch. The math rewards a board with a high-power creature sitting back: a four-power blocker becomes a four-damage shot aimed at the air, repeatable each turn so long as you can keep feeding it a fresh untapped creature. It is colorless, which is the real point, since the green and red of its era leaned on reach-style bodies and one-off burn to fight flyers; this hands any deck a permanent answer that scales with its own board. The friction (per-use mana, the artifact tapping itself, the creature pulled off offense for a turn, the tight targeting) keeps the engine honest. It is a slow, conditional, deliberately gated tool from a time when fixed defensive answers were the norm and flying was an evasion problem worth building a machine to solve.