Undead Sprinter, Birgi, God of Storytelling // Harnfel, Horn of Bounty, and Phyrexian Altar

Prerequisites

• Undead Sprinter on the battlefield
• Birgi, God of Storytelling // Harnfel, Horn of Bounty on the battlefield
• Phyrexian Altar on the battlefield
• A non-Zombie creature has died this turn
• available

Steps

1. Activate Phyrexian Altar by sacrificing Undead Sprinter, adding
2. Cast Undead Sprinter from your graveyard by paying
3. Birgi triggers, adding
4. Activate Phyrexian Altar by sacrificing Undead Sprinter, adding
5. Repeat from step 2

Results

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