Time Sieve, Myr Battlesphere, Thassa, Deep-Dwelling, and Thopter Spy Network

Prerequisites

• Time Sieve on the battlefield
• Myr Battlesphere on the battlefield
• Thassa, Deep-Dwelling on the battlefield
• Thopter Spy Network on the battlefield

Steps

1. At the beginning of your upkeep, Thopter Spy Network's first ability triggers, creating a 1/1 Thopter artifact creature token
2. At the beginning of your end step, Thassa triggers, blinking Myr Battlesphere
3. When Myr Battlesphere enters the battlefield, its first ability triggers, creating four 1/1 Myr artifact creature tokens
4. Activate Time Sieve by tapping it, sacrificing the Thopter and the four Myrs, causing you to take an extra turn after this one
5. Repeat each turn

Results

• Infinite turns