Sharuum the Hegemon, Coretapper, Magistrate's Scepter, and Don & Leo, Problem Solvers

Prerequisites

• Sharuum the Hegemon on the battlefield
• Coretapper on the battlefield
• Magistrate's Scepter on the battlefield
• Don & Leo, Problem Solvers on the battlefield

Steps

1. Activate Coretapper's first ability by tapping it, putting a charge counter on Magistrate's Scepter
2. Activate Coretapper's second ability by sacrificing it, putting two charge counters on Magistrate's Scepter
3. 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
4. At the beginning of your end step, Don & Leo triggers, blinking Sharuum
5. When Sharuum enters the battlefield, it triggers, returning Coretapper from your graveyard to the battlefield
6. Repeat each turn

Results

• Infinite turns
• Lock