Gravespawn Sovereign, Death Cultist, and Intruder Alarm

Prerequisites

• Gravespawn Sovereign on the battlefield
• Death Cultist on the battlefield
• Intruder Alarm on the battlefield
• At least four other Zombies on the battlefield

Steps

1. Sacrifice Death Cultist to have target opponent lose 1 life and you gain 1 life
2. Tap 5 untapped zombies you control to return Death Cultist to the battlefield
3. Intruder Alarm triggers, untapping all creatures
4. Repeat

Results

• Infinite death triggers
• Infinite ETB
• Infinite lifegain
• Infinite lifeloss
• Infinite LTB