Toph, the First Metalbender + Toph, Hardheaded Teacher + Umbral Collar Zealot + Dimir Aqueduct

Toph, the First Metalbender

Toph, Hardheaded Teacher

Umbral Collar Zealot

Dimir Aqueduct

How it works

1. Cast the artifact by paying 0.
2. Toph, Hardheaded Teacher triggers, earthbending Dimir Aqueduct.
3. Resolve the artifact spell.
4. Activate Umbral Collar Zealot by sacrificing Dimir Aqueduct.
5. When Dimir Aqueduct dies, Toph, Hardheaded Teach triggers, returning Dimir Aqueduct from your graveyard to the battlefield tapped.
6. When Dimir Aqueduct enters, it triggers, returning the artifact cast in step 1 from the battlefield to your hand, as it's a land due to Toph, the First Metalbender.
7. Resolve the Umbral Collar Zealot ability
8. Repeat.

This clever loop turns a zero-cost artifact into an engine of endless iteration by weaponizing the unique typeline manipulation of Toph, the First Metalbender. Because Toph, the First Metalbender makes your nontoken artifacts into lands, Dimir Aqueduct can bounce it back to your hand every time the bounceland enters the battlefield. Meanwhile, Umbral Collar Zealot provides the sacrifice outlet to send Dimir Aqueduct to the graveyard, which immediately triggers Toph, Hardheaded Teacher to rescue it back to the battlefield tapped. You can repeat this entire cycle indefinitely, fueling your triggers with the help of Toph, Hardheaded Teacher's spell-casting payoffs and Umbral Collar Zealot's surveil engine.