Toph, the First Metalbender + Toph, Hardheaded Teacher + Phyrexian Altar + Guildless Commons

Toph, the First Metalbender

Toph, Hardheaded Teacher

Phyrexian Altar

Guildless Commons

How it works

1. Cast the artifact by paying 0.
2. Toph, Hardheaded Teacher triggers, earthbending Guildless Commons.
3. Resolve the artifact spell.
4. Activate Phyrexian Altar by sacrificing Guildless Commons.
5. When Guildless Commons dies, Toph, Hardheaded Teach triggers, returning Guildless Commons from your graveyard to the battlefield tapped.
6. When Guildless Commons 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 clever loop turns the zero-mana artifact you cast into a bouncing land thanks to Toph, the First Metalbender, which permanently makes all your nontoken artifacts into lands. Every time you recast that artifact, Toph, Hardheaded Teacher triggers to earthbend Guildless Commons into a creature so you can feed it to Phyrexian Altar for any color of mana. When Guildless Commons hits the graveyard, Toph, Hardheaded Teacher's own earthbending return-to-battlefield safety net triggers to bring it right back tapped, which in turn triggers Guildless Commons' bounce ability to scoop the artifact back to your hand for another iteration.