Roon of the Hidden Realm, Eternal Witness, and Walk the Aeons

Prerequisites

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

Steps

1. Cast Walk the Aeons 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 Walk the Aeons into your hand from your graveyard
5. Repeat each turn

Results

• Infinite turns