Cauldron of Souls, Dross Scorpion, Shilgengar, Sire of Famine, and Encroaching Mycosynth

Prerequisites

• Cauldron of Souls on the battlefield
• Dross Scorpion on the battlefield
• Shilgengar, Sire of Famine on the battlefield
• Encroaching Mycosynth on the battlefield

Steps

1. Activate Cauldron of Souls by tapping it, giving the creature with bloodthirst persist until end of turn
2. Activate Shilgengar by sacrificing the creature with bloodthirst
3. When the creature dies, its persist ability and Dross Scorpion trigger
4. Resolve the persist trigger, returning the creature from your graveyard to the battlefield, which enters the battlefield with at least one +1/+1 counter on it due to its bloodthirst ability
5. Resolve the Dross Scorpion trigger, untapping Cauldron of Souls
6. Resolve the Shilgengar ability Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite Blood tokens