Erratic Portal, and Emrakul, the Aeons Torn

Prerequisites

• Erratic Portal on the battlefield
• Emrakul, the Aeons Torn in hand or in the command zone
• each turn plus enough mana to pay commander tax on the first turn, if applicable available

Steps

1. Cast Emrakul by paying and commander tax, if applicable
2. Emrakul triggers, causing you to get an extra turn after this one
3. Activate Erratic Portal by paying and tapping it, choosing not to pay and return Emrakul from the battlefield to your hand
4. Repeat each turn

Results

• Infinite turns