Thassa, Deep-Dwelling, Eternal Witness, and Time Stretch

Prerequisites

• Thassa, Deep-Dwelling on the battlefield
• Eternal Witness on the battlefield
• Time Stretch in hand
• every other turn available

Steps

1. Cast Time Stretch by paying , getting two extra turns after this one
2. At the beginning of your end step, Thassa triggers, blinking Eternal Witness
3. Eternal Witness enters the battlefield, returning Time Stretch from your graveyard to your hand
4. Repeat every other turn

Results

• Infinite turns