Marina Vendrell, Unholy Annex // Ritual Chamber, Intruder Alarm, and Fatestitcher

Prerequisites

• Marina Vendrell on the battlefield
• Unholy Annex // Ritual Chamber on the battlefield
• Intruder Alarm on the battlefield
• Fatestitcher on the battlefield

Steps

1. Activate Marina by tapping it, unlocking Ritual Chamber
2. Ritual Chamber triggers, creating a 6/6 Demon creature token with flying
3. When the Demon enters the battlefield, Intruder Alarm triggers, untapping all creatures
4. Activate Marina by tapping it, locking Ritual Chamber
5. Activate Fatestitcher by tapping it, untapping Marina
6. Repeat

Results

• Infinite ETB
• Infinite creature tokens
• Infinite mana creatures you control can produce
• Infinite untap of all creatures