Magnanimous Magistrate, Doubling Season, Martyr for the Cause, and Ashnod's Altar

Prerequisites

• Magnanimous Magistrate on the battlefield
• Doubling Season on the battlefield
• Martyr for the Cause on the battlefield
• Ashnod's Altar on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Martyr for the Cause, adding
2. Martyr for the Cause dies, triggering itself and Magnanimous Magistrate
3. Resolve the Martyr for the Cause trigger, causing you to proliferate, putting two reprieve counters on Magnanimous Magistrate
4. Resolve the Magnanimous Magistrate trigger, causing you to remove two reprieve counters from Magnanimous Magistrate and return Martyr for the Cause from your graveyard to the battlefield
5. Repeat

Results

• Infinite colorless mana
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite proliferate
• Infinite sacrifice triggers