Yenna, Redtooth Regent, Airtight Alibi, Careful Cultivation, and Thaumatog

Prerequisites

• Yenna, Redtooth Regent on the battlefield
• Airtight Alibi on the battlefield
• Careful Cultivation on the battlefield
• Thaumatog on the battlefield
• available

Steps

1. Activate Yenna by paying and tapping it, creating a copy of Airtight Alibi attached to Yenna, and then untapping Yenna and causing you to scry 2
2. When the Airtight Alibi token enters, it triggers
3. Holding priority, activate Yenna by tapping it, adding
4. Resolve the Airtight Alibi trigger, untapping Yenna
5. Activate Thaumatog by sacrificing the Airtight Alibi token
6. Repeat

Results

• Infinite lifegain triggers
• Infinite lifegain
• Infinite scry 2
• Infinitely large Thaumatog until end of turn