Toph, the First Metalbender + Toph, Hardheaded Teacher + Boros Garrison + Coastal Hornclaw

Toph, the First Metalbender

Toph, Hardheaded Teacher

Boros Garrison

Coastal Hornclaw

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 Coastal Hornclaw 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. Resolve the Coastal Hornclaw ability
8. Repeat.

This brilliant loop turns your mana bases and zero-mana artifacts into an endless engine of sacrifice and landfall. With Toph, the First Metalbender transforming your nontoken artifacts into lands, any zero-mana artifact you cast doubles as a permanent you can feed to Coastal Hornclaw. When you sacrifice Boros Garrison to pay for Coastal Hornclaw's flying activation, its death triggers Toph, Hardheaded Teacher to immediately bring it right back to the battlefield. Finally, the entering Boros Garrison's own trigger forces you to bounce that original artifact back to your hand, allowing you to recast it and trigger Toph, Hardheaded Teacher all over again for an infinite cascade of triggers.