Toph, the First Metalbender + Toph, Hardheaded Teacher + Woe Strider + Rakdos Carnarium

Toph, the First Metalbender

Toph, Hardheaded Teacher

Woe Strider

Rakdos Carnarium

How it works

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

This crafty loop turns a free artifact into an infinite engine by weaving together the unique rules interactions of all four cards. Toph, the First Metalbender acts as the foundational catalyst, turning your cheap nontoken artifacts into lands so they can be targeted and bounced. Whenever you cast that spell, Toph, Hardheaded Teacher triggers to earthbend Rakdos Carnarium into an active creature, which you then sacrifice to Woe Strider to trigger scry 1 and send the carnarium to the graveyard. Because Rakdos Carnarium is a land, its death triggers Toph, Hardheaded Teacher to return it to the battlefield tapped, and its subsequent entry triggers its own bounce ability to pick up your original artifact so you can recast it all over again.