Time Sieve, Endless Ranks of the Dead, and Encroaching Mycosynth

Prerequisites

• Time Sieve on the battlefield
• Endless Ranks of the Dead on the battlefield
• Encroaching Mycosynth on the battlefield
• You control at least ten Zombies

Steps

1. At the beginning of your upkeep, Endless Ranks of the Dead triggers, creating at least five 2/2 Zombie creature tokens that are artifacts due to Encroaching Mycosynth
2. Activate Time Sieve by tapping it and sacrificing five Zombies, causing you to take an extra turn after this one
3. Repeat each turn

Results

• Infinite turns