Leonardo, Sewer Samurai, Solemnity, and Phyrexian Altar

Prerequisites

• Leonardo, Sewer Samurai on the battlefield
• Solemnity on the battlefield
• Phyrexian Altar on the battlefield

Steps

1. Activate Phyrexian Altar by sacrificing the additional creature, adding one mana of any color
2. Cast the creature from your graveyard by paying its mana cost
3. It will not enter with a finality counter on it due to Solemnity
4. Repeat

Results

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