Time Sieve, Myr Battlesphere, Conjurer's Closet, and Gandalf the White

Prerequisites

• Time Sieve on the battlefield
• Myr Battlesphere on the battlefield
• Conjurer's Closet on the battlefield
• Gandalf the White on the battlefield

Steps

1. At the beginning of your end step, Conjurer's Closet triggers, blinking Myr Battlesphere
2. When Myr Battlesphere enters the battlefield, its first ability triggers twice, creating eight 1/1 Myr artifact creature tokens
3. Activate Time Sieve by tapping it and sacrificing five Myrs, causing you to take an extra turn after this one
4. Repeat each turn

Results

• Infinite turns