Ravos, Soultender, Time Sieve, and Myr Battlesphere

Prerequisites

• Ravos, Soultender on the battlefield
• Time Sieve on the battlefield
• Myr Battlesphere in the graveyard
• each turn available

Steps

1. At the beginning of your upkeep, Ravos triggers, returning Myr Battlesphere from your graveyard to your hand
2. Cast Myr Battlesphere by paying
3. When Myr Battlesphere enters the battlefield, it triggers, creating four 1/1 Myr artifact creature tokens
4. 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
5. Repeat each turn

Results

• Infinite turns