Time Sieve + Endless Ranks of the Dead + Encroaching Mycosynth

Time Sieve

Endless Ranks of the Dead

Encroaching Mycosynth

How it works

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.