Toph, the First Metalbender + Toph, Hardheaded Teacher + Umbral Collar Zealot + Selesnya Sanctuary

Toph, the First Metalbender

Toph, Hardheaded Teacher

Umbral Collar Zealot

Selesnya Sanctuary

How it works

1. Cast the artifact by paying 0.
2. Toph, Hardheaded Teacher triggers, earthbending Selesnya Sanctuary.
3. Resolve the artifact spell.
4. Activate Umbral Collar Zealot by sacrificing Selesnya Sanctuary.
5. When Selesnya Sanctuary dies, Toph, Hardheaded Teach triggers, returning Selesnya Sanctuary from your graveyard to the battlefield tapped.
6. When Selesnya Sanctuary 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 cunning loop relies on Toph, the First Metalbender turning your nontoken artifacts into lands, effectively expanding your mana and land-based interactions to include your artifact collection. By casting a zero-mana artifact, you trigger Toph, Hardheaded Teacher to animate Selesnya Sanctuary via earthbend, making it vulnerable to Umbral Collar Zealot's sacrifice ability. When Selesnya Sanctuary is sacrificed to fuel Umbral Collar Zealot, its death triggers Toph, Hardheaded Teacher to return it to the battlefield, where its own entry trigger bounces the original zero-mana artifact back to your hand thanks to its newly acquired land type.