Emry, Lurker of the Loch, Ugin's Nexus, Isochron Scepter, Pull from Eternity, and Grinding Station

Prerequisites

• Emry, Lurker of the Loch on the battlefield
• Ugin's Nexus on the battlefield
• Isochron Scepter on the battlefield
• Pull from Eternity in exile
• Grinding Station on the battlefield
• each extra turn available

Steps

1. Activate Grinding Station by tapping it and sacrificing Ugin's Nexus, causing target player to mill three cards
2. When Ugin's Nexus is sacrificed, it is exiled instead of being put into your graveyard, causing you to take an extra turn after this one
3. Move to your next turn
4. Activate Isochron Scepter by paying and tapping it, casting a copy of Pull from Eternity without paying its mana cost
5. Resolve Pull from Eternity, putting Ugin's Nexus from exile into your graveyard
6. Activate Emry by tapping it, targeting Ugin's Nexus
7. Cast Ugin's Nexus from your graveyard by paying
8. When Ugin's Nexus enters the battlefield, Grinding Station triggers, untapping Grinding Station
9. Repeat

Results

• Infinite turns