Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Boss's Chauffeur, and Altar of Dementia

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Boss's Chauffeur on the battlefield
• Altar of Dementia on the battlefield

Steps

1. Activate Altar of Dementia by sacrificing Boss's Chauffeur
2. When Boss's Chauffeur dies, its persist ability and second ability trigger
3. Resolve the second trigger, creating a number of 1/1 Citizen creature tokens equal to the number of +1/+1 counters that were on Boss's Chauffeur
4. Resolve the persist trigger, returning Boss's Chauffeur from your graveyard to the battlefield
5. It'll enter with a number of +1/+1 counters on it equal to the number of creatures you control minus 1 due to its replacement effect
6. Resolve the Altar of Dementia ability
7. Repeat

Results

• Infinite +1/+1 counters on a creature
• Infinite ETB
• Infinite LTB
• Infinite creature tokens
• Infinite death triggers
• Infinite mill
• Infinite sacrifice triggers
• Infinite self-mill