Toph, the First Metalbender + Toph, Hardheaded Teacher + Thermopod + Boros Garrison

Toph, the First Metalbender

Toph, Hardheaded Teacher

Thermopod

Boros Garrison

How it works

1. Cast the artifact by paying 0.
2. Toph, Hardheaded Teacher triggers, earthbending Boros Garrison.
3. Resolve the artifact spell.
4. Activate Thermopod by sacrificing Boros Garrison.
5. When Boros Garrison dies, Toph, Hardheaded Teach triggers, returning Boros Garrison from your graveyard to the battlefield tapped.
6. When Boros Garrison 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. Repeat.

This loop transforms a zero-mana artifact into an infinite engine by leveraging Toph, the First Metalbender, which turns your nontoken artifacts into lands. With that foundation set, casting the artifact triggers Toph, Hardheaded Teacher to animate Boros Garrison into a creature, allowing you to feed it to Thermopod for red mana. Because Boros Garrison is treated as a land by Toph, the First Metalbender, its death safely triggers Toph, Hardheaded Teacher to return it to the battlefield, where its own entry trigger bounces the original artifact back to your hand to start over.