Magistrate's Scepter, Energy Chamber, and Tawnos, Urza's Apprentice

Prerequisites

• Magistrate's Scepter on the battlefield
• Energy Chamber on the battlefield
• Tawnos, Urza's Apprentice on the battlefield
• Magistrate's Scepter has three charge counters on it
• each turn available

Steps

1. Activate Magistrate's Scepter, removing 3 charge counters to take an extra turn
2. Activate Tawnos, copying the extra turn ability
3. Pass the turn
4. At the beginning of your upkeep, Energy Chamber triggers, putting a charge counter on Magistrate's Scepter
5. Activate Magistrate's Scepter, putting a charge counter on itself
6. Activate Tawnos, copying the trigger
7. Pass the turn
8. Repeat

Results

• Infinite turns