Coretapper, Magistrate's Scepter, Debtors' Knell, and Thousand-Year Elixir

Prerequisites

• Coretapper in the graveyard
• Magistrate's Scepter on the battlefield
• Debtors' Knell on the battlefield
• Thousand-Year Elixir on the battlefield

Steps

1. At the beginning of your upkeep, Debtors' Knell triggers, returning Coretapper from your graveyard to the battlefield
2. Activate Coretapper's first ability by tapping it, putting a charge counter on Magistrate's Scepter
3. Activate Coretapper's second ability by sacrificing it, putting two charge counters on Magistrate's Scepter
4. 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
5. Repeat each turn

Results

• Infinite turns