Toph, the First Metalbender, Grinding Station, and Biotransference

Prerequisites

• Toph, the First Metalbender on the battlefield
• Grinding Station on the battlefield
• Biotransference on the battlefield

Steps

1. Cast the earthbend creature by paying its mana cost
2. When the creature enters, it and Grinding Station trigger
3. Resolve the creature's trigger, earthbending the creature, as it's an artifact due to Biotransference, thus making it also a land due to Toph
4. Resolve the Grinding Station trigger, untapping it
5. Activate Grinding Station by tapping it and sacrificing the earthbent creature
6. When the creature dies, it triggers, returning it from your graveyard to the battlefield tapped
7. Repeat steps 2 through 4 once
8. Resolve the Grinding Station ability from step 5, causing a player to mill three cards Repeat from step 5

Results

• Infinite artifact ETB
• Infinite artifact LTB
• Infinite artifact sacrifice triggers
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers
• Infinite landfall triggers
• Infinite mill
• Infinite self-mill