Roon of the Hidden Realm, Eternal Witness, and Time Warp

Prerequisites

• Roon of the Hidden Realm on the battlefield
• Eternal Witness on the battlefield
• Time Warp in hand
• Roon does not have summoning sickness
• each turn available

Steps

1. Cast Time Warp by paying , causing you to take an extra turn after this one
2. Activate Roon by paying and tapping it, exiling Eternal Witness until the beginning of your end step
3. At the beginning of your end step, Roon triggers, returning Eternal Witness from exile to the battlefield
4. Eternal Witness enters the battlefield, putting Time Warp into your hand from your graveyard
5. Repeat each turn

Results

• Infinite turns