Teleportation Circle, Eternal Witness, and Time Stretch

Prerequisites

• Teleportation Circle on the battlefield
• Eternal Witness on the battlefield
• Time Stretch in hand
• every other turn available

Steps

1. Cast Time Stretch by paying , causing you to take two extra turns after this one
2. At the beginning of your end step, Teleportation Circle triggers, blinking Eternal Witness
3. When Eternal Witness enters the battlefield, it triggers, returning Time Stretch to your hand from your graveyard
4. Repeat during each even-numbered extra turn

Results

• Infinite turns