Magosi, the Waterveil + The Ozolith + Nature's Revolt + Karn's Bastion

Magosi, the Waterveil

The Ozolith

Nature's Revolt

Karn's Bastion

How it works

1. During your precombat main phase, use Karn's Bastion 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 Nature's Revolt, 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.