Mirko, Obsessive Theorist, Coretapper, Magistrate's Scepter, and Power Conduit

Prerequisites

• Mirko, Obsessive Theorist on the battlefield
• Coretapper on the battlefield
• Magistrate's Scepter on the battlefield
• Power Conduit on the battlefield
• Magistrate's Scepter has at least one charge counter on it
• Mirko has at least 2 power

Steps

1. Activate Coretapper's second ability by sacrificing it, putting two charge counters on Magistrate's Scepter
2. Activate Magistrate's Scepter's second ability by tapping it and removing three charge counters from it, causing you to take an extra turn after this one
3. At the beginning of your end step, Mirko's last ability triggers, returning Coretapper from your graveyard to the battlefield with a finality counter on it
4. Activate Power Conduit by tapping it and removing the finality counter from Coretapper, putting a charge counter on Magistrate's Scepter
5. Repeat from step 2 each turn

Results

• Infinite turns