Ashnod's Altar, Mayhem Devil, Pitiless Plunderer, and Tenacious Dead

Prerequisites

• Ashnod's Altar on the battlefield
• Mayhem Devil on the battlefield
• Pitiless Plunderer on the battlefield
• Tenacious Dead on the battlefield

Steps

1. Sacrifice Tenacious Dead to Ashnod's Altar, generating
2. Pitiless Plunderer, Mayhem Devil, and Tenacious Dead trigger; stack the triggers to resolve in that order
3. Pitiless Plunderer generates a Treasure token; crack it to float
4. Mayhem Devil triggers again
5. Both Mayhem Devil triggers deals 1 damage each to an opponent for 2 damage
6. Resolve the Tenacious Dead trigger, paying to return it to the battlefield from the graveyard
7. Repeat the sacrifice-recursion loop inflicting damage to opponent infinitely with Mayhem Devil triggers

Results

• Infinite colorless mana
• Infinite damage
• Infinite death triggers
• Infinite ETB
• Infinite LTB
• Infinite sacrifice triggers