Cauldron of Souls, Dross Scorpion, Grinding Station, and Encroaching Mycosynth

Prerequisites

• Cauldron of Souls on the battlefield
• Dross Scorpion on the battlefield
• Grinding Station on the battlefield
• Encroaching Mycosynth on the battlefield
• An opponent was dealt damage this turn
• The creature with bloodthirst does not have a -1/-1 counter on it

Steps

1. Activate Cauldron of Souls by tapping it, giving the creature with bloodthirst persist until end of turn
2. Activate Grinding Station by tapping it and 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. When the creature enters the battlefield, Grinding Station triggers, untapping Grinding Station
6. Resolve the Dross Scorpion trigger, untapping Cauldron of Souls
7. Resolve the Grinding Station ability from step 2, causing target player to mill three cards
8. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite mill
• Infinite self-mill