Fool's Demise, Mana Echoes, and Phyrexian Altar

Prerequisites

• Fool's Demise on the battlefield
• Mana Echoes on the battlefield
• Phyrexian Altar on the battlefield
• available

Steps

1. Activate Phyrexian Altar by sacrificing the creature with Fool's Demise attached, adding
2. The creature dies, triggering Fool's Demise's first and second abilities
3. Resolve the first Fool's Demise trigger, returning the creature from your graveyard to the battlefield
4. The creature enters the battlefield, triggering Mana Echoes, adding at least
5. Resolve the second Fool's Demise trigger, returning it from your graveyard to your hand
6. Cast Fool's Demise by paying , attaching it to the creature
7. Repeat

Results

• Infinite colorless mana
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers
• Infinite storm count