Magosi, the Waterveil, The Ozolith, Living Plane, and Cayth, Famed Mechanist

Prerequisites

• Magosi, the Waterveil on the battlefield
• The Ozolith on the battlefield
• Living Plane on the battlefield
• Cayth, Famed Mechanist on the battlefield
• available

Steps

1. During your precombat main phase, use Cayth to put an additional eon counter on Magosi
2. Activate Magosi's third ability by tapping it, removing an eon counter from it and returning it from the battlefield to your hand
3. When Magosi leaves the battlefield, The Ozolith's first ability triggers due to Living Plane, putting an eon counter on The Ozolith
4. Resolve the Magosi ability, causing you to take an extra turn after this one
5. Play Magosi
6. At the beginning of your combat phase, The Ozolith triggers, moving an eon counter from itself onto Magosi
7. Repeat each turn

Results

• Infinite turns
• Lock