Thopter Foundry

The engine half of a two-card combo that turns dead artifacts into an arbitrary stream of fliers and life. On its own it converts one nontoken artifact into one Thopter and one life per activation, which is fine value; paired with Sword of the Meek, it stops being incremental. Sacrifice the Sword to the Foundry, make a Thopter, and the Sword's own trigger returns it to the battlefield whenever a 1/1 enters under your control. Each cycle costs only the activation mana, so with any way to refund or generate that mana you loop indefinitely: infinite Thopters, infinite life, an army that wins through the air. The reanimation clause living on Sword of the Meek rather than the Foundry is what makes the loop tick, an interaction that reads as innocuous on either card and lethal once both sit on the table. The flexible white-or-black pip in its cost reflects a home in a three-color shard while letting it slot into either side of an artifact build, a small concession for a piece that mostly wants a Sword to feed it. As a design it is a clean demonstration of how a sacrifice outlet plus a self-returning equipment manufacture a closed loop the moment both halves are in play, no third piece required beyond a mana source.