Time Sieve + Encroaching Mycosynth + Helm of the Host + Master of Waves

Prerequisites

• Helm of the Host attached to Master of Waves.
• Your devotion to blue is at least four.

Steps

1. 1At the beginning of your combat phase, Helm of the Host triggers, creating a token copy of Master of Waves with haste.
2. 2When the Master of Waves token enters the battlefield, it triggers, creating a number of 1/0 Elemental creature tokens equal to your devotion to blue.
3. 3Activate Time Sieve by tapping it and sacrificing five creature tokens, causing you to take an extra turn after this one.
4. 4Repeat each turn.

Effects

• Infinite turns
• Lock