Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Ceti Eel, and Carrion Feeder

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Ceti Eel on the battlefield
• Carrion Feeder on the battlefield

Steps

1. Activate Carrion Feeder by sacrificing Ceti Eel
2. When Ceti Eel dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. When Ceti Eel enters, it triggers, causing you to mill two cards and put a +1/+1 counter on it
4. Resolve the Carrion Feeder ability
5. Repeat

Results

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