Time Sieve, Myr Battlesphere, and Avacyn, Angel of Horror

Prerequisites

• Time Sieve on the battlefield
• Myr Battlesphere in hand
• Avacyn, Angel of Horror on the battlefield
• available

Steps

1. Cast Myr Battlesphere by paying
2. When Myr Battlesphere enters, it triggers, creating four 1/1 Myr creature tokens
3. Activate Time Sieve by tapping it, sacrificing Myr Battlesphere and sacrificing the four Myr tokens, causing you to take an extra turn after this one
4. At the beginning of your end step, Avacyn triggers, returning Myr Battlesphere from your graveyard to the battlefield
5. When Myr Battlesphere enters, it triggers, creating four 1/1 Myr creature tokens
6. Repeat from step 3 each turn

Results

• Infinite turns
• Lock