Toph, the First Metalbender + Toph, Hardheaded Teacher + Umbral Collar Zealot + Arid Archway

Toph, the First Metalbender

Toph, Hardheaded Teacher

Umbral Collar Zealot

Arid Archway

How it works

1. Cast the artifact by paying 0.
2. Toph, Hardheaded Teacher triggers, earthbending Arid Archway.
3. Resolve the artifact spell.
4. Activate Umbral Collar Zealot by sacrificing Arid Archway.
5. When Arid Archway dies, Toph, Hardheaded Teach triggers, returning Arid Archway from your graveyard to the battlefield tapped.
6. When Arid Archway 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 loop transforms a free artifact into an infinite engine by leveraging Toph, the First Metalbender's static ability to turn nontoken artifacts into lands, making them valid targets for Arid Archway's bounce trigger. When you sacrifice that animated artifact-land to Umbral Collar Zealot's activation, its death immediately triggers Toph, Hardheaded Teacher to return it to the battlefield tapped. This reentry triggers Arid Archway's bounce ability anew to pick up the artifact, allowing you to recast it for zero mana and endlessly repeat the sequence for infinite death triggers, storm count, and surveil.