Toph, the First Metalbender, Toph, Hardheaded Teacher, Ashnod's Altar, and Arid Archway

Prerequisites

• Toph, the First Metalbender on the battlefield
• Toph, Hardheaded Teacher on the battlefield
• Ashnod's Altar on the battlefield
• Arid Archway on the battlefield

Steps

1. Cast the artifact by paying
2. Toph, Hardheaded Teacher triggers, earthbending Arid Archway
3. Resolve the artifact spell
4. Activate Ashnod's Altar by sacrificing Arid Archway
5. When Arid Archway dies, Toph, Hardheaded Teach triggers, returning Arid Archway from your graveyard to the battlefield tapped
6. When Arid Archway 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

Results

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