Panoptic Mirror, and Rise of the Eldrazi

Prerequisites

• Panoptic Mirror on the battlefield
• Rise of the Eldrazi in exile

Steps

1. At the beginning of your upkeep, Panoptic Mirror triggers, casting a copy of Rise of the Eldrazi without paying its mana cost
2. Resolve Rise of the Eldrazi, causing you to take an extra turn after this one
3. Repeat each turn

Results

• Infinite turns