Toph, the First Metalbender + Toph, Hardheaded Teacher + Carrion Feeder + Azorius Chancery

Toph, the First Metalbender

Toph, Hardheaded Teacher

Carrion Feeder

Azorius Chancery

How it works

1. Cast the artifact by paying 0.
2. Toph, Hardheaded Teacher triggers, earthbending Azorius Chancery.
3. Resolve the artifact spell.
4. Activate Carrion Feeder by sacrificing Azorius Chancery.
5. When Azorius Chancery dies, Toph, Hardheaded Teach triggers, returning Azorius Chancery from your graveyard to the battlefield tapped.
6. When Azorius Chancery 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 Carrion Feeder ability
8. Repeat.

This clever loop transforms a free artifact into an infinite engine by leveraging Toph, the First Metalbender, whose static ability turns all your nontoken artifacts into lands. With that foundation set, you cast your artifact for zero mana to trigger Toph, Hardheaded Teacher, earthbending Azorius Chancery into an animated land creature so it can be sacrificed to Carrion Feeder. Because Azorius Chancery is a land, its death triggers Toph, Hardheaded Teacher's safety clause to return it straight to the battlefield tapped, which in turn causes Azorius Chancery's own entry trigger to bounce your original artifact right back to your hand to start the cycle anew.