Mortuary, Wild Cantor, Bolas's Citadel, and Arnyn, Deathbloom Botanist

Prerequisites

• Mortuary on the battlefield
• Wild Cantor in hand
• Bolas's Citadel on the battlefield
• Arnyn, Deathbloom Botanist on the battlefield

Steps

1. Cast Wild Cantor by paying its mana cost
2. Activate Wild Cantor by sacrificing it
3. When Wild Cantor dies, Mortuary and Arnyn trigger
4. Resolve the Mortuary trigger, putting Wild Cantor 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 Wild Cantor from the top of your library by paying 1 life
7. Repeat from step 2

Results

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