Phantom Steed, Godo, Bandit Warlord, Lumbering Battlement, Xenograft, and Urabrask the Hidden

Prerequisites

• Phantom Steed on the battlefield
• Godo, Bandit Warlord on the battlefield
• Lumbering Battlement in exile
• Xenograft on the battlefield
• Urabrask the Hidden on the battlefield
• "Samurai" chosen with Xenograft
• An opponent cannot block and kill creatures you control

Steps

1. Declare Phantom Steed and Godo as attackers, triggering their abilities
2. Resolve the Godo trigger, untapping all creatures you control and causing you to get an additional combat phase after this one
3. Resolve the Phantom Steed trigger, creating a token copy of Lumbering Battlement
4. The token Lumbering Battlement enters the battlefield, exiling Godo until Lumbering Battlement leaves the battlefield
5. At the end of your combat phase, the token Lumbering Battlement triggers, causing you to sacrifice it
6. The token Lumbering Battlement leaves the battlefield, returning Godo from exile to the battlefield
7. Repeat each combat phase

Results

• Infinite combat phases
• Infinite ETB
• Infinite LTB
• Infinite mana creatures you control can produce
• Infinite untap of creatures you control