Gravespawn Sovereign, Intruder Alarm, and Viscera Seer

Prerequisites

• Gravespawn Sovereign on the battlefield
• Intruder Alarm on the battlefield
• Viscera Seer on the battlefield
• You control at least four other Zombies

Steps

1. Activate Viscera Seer by sacrificing itself, causing you to scry 1
2. Activate Gravespawn Sovereign by tapping five untapped Zombies you control, returning Viscera Seer from your graveyard to the battlefield
3. Viscera Seer enters the battlefield, triggering Intruder Alarm, untapping all creatures
4. Repeat

Results

• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers
• Infinite scry 1
• Infinite untap of creatures