Prototype Portal, Clock of Omens, Grinding Station, and Treasure Vault

Prerequisites

• Prototype Portal on the battlefield
• Clock of Omens on the battlefield
• Grinding Station on the battlefield
• Treasure Vault in exile

Steps

1. Activate Prototype Portal by paying and tapping it, creating a token copy of Treasure Vault
2. The Treasure Vault token enters, triggering Grinding Station, untapping Grinding Station
3. Activate Clock of Omens by tapping the Treasure Vault token and Grinding Station, untapping Prototype Portal
4. Repeat

Results

• Infinite landfall triggers
• Infinite tapped land tokens