Mortuary, Bolas's Citadel, Viscera Seer, and Arnyn, Deathbloom Botanist

Prerequisites

• Mortuary on the battlefield
• Bolas's Citadel on the battlefield
• Viscera Seer in hand
• Arnyn, Deathbloom Botanist on the battlefield

Steps

1. Cast Viscera Seer by paying its mana cost
2. Activate Viscera Seer by sacrificing it
3. When Viscera Seer dies, Mortuary and Arnyn trigger
4. Resolve the Mortuary trigger, putting Viscera Seer from your graveyard onto the top of your library
5. Resolve the Arnyn trigger, causing target opponent to lose 2 life and you to gain 2 life
6. Cast Viscera Seer from the top of your library by paying 1 life
7. Repeat from step 2

Results

• Infinite creature ETB
• Infinite creature LTB
• Infinite death triggers
• Infinite lifegain triggers
• Infinite lifeloss
• Infinite creature sacrifice triggers
• Infinite storm count