Toph, the First Metalbender, Toph, Hardheaded Teacher, Yahenni, Undying Partisan, and Boros Garrison

Prerequisites

• Toph, the First Metalbender on the battlefield
• Toph, Hardheaded Teacher on the battlefield
• Yahenni, Undying Partisan on the battlefield
• Boros Garrison on the battlefield

Steps

1. Cast the artifact by paying
2. Toph, Hardheaded Teacher triggers, earthbending Boros Garrison
3. Resolve the artifact spell
4. Activate Yahenni 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 Yahenni ability Repeat

Results

• Infinite creature ETB
• Infinite creature LTB
• Infinite death triggers
• Infinite landfall triggers
• Infinite creature sacrifice triggers
• Infinite storm count