Time Sieve, Encroaching Mycosynth, Rionya, Fire Dancer, and Lena, Selfless Champion

Prerequisites

• Time Sieve on the battlefield
• Encroaching Mycosynth on the battlefield
• Rionya, Fire Dancer on the battlefield
• Lena, Selfless Champion on the battlefield
• You control at least five nontoken creatures

Steps

1. At the beginning of your combat phase, Rionya triggers, creating at least one token copy of Lena with haste
2. Put the Lena token into your graveyard due to the legend rule
3. The Lena token enters-the-battlefield ability triggers, creating at least five 1/1 Soldier creature tokens
4. Activate Time Sieve by tapping it, sacrificing the Lena token and the Soldier tokens, causing you to take an extra turn after this one
5. Repeat each turn

Results

• Infinite turns