Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Umbral Collar Zealot, and Big Mother Mouser

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Umbral Collar Zealot on the battlefield
• Big Mother Mouser on the battlefield

Steps

1. Activate Umbral Collar Zealot by sacrificing Big Mother Mouser
2. When Big Mother Mouser dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to its replacement effect
3. Resolve the Umbral Collar Zealot ability
4. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite creature tokens
• Infinite death triggers
• Infinite sacrifice triggers
• Infinite surveil