Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Umbral Collar Zealot, and Spiteful Squad

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Umbral Collar Zealot on the battlefield
• Spiteful Squad on the battlefield

Steps

1. Activate Umbral Collar Zealot by sacrificing Spiteful Squad
2. When Spiteful Squad 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 +1/+1 counters on creatures you control
• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite recursion of creatures you control
• Infinite sacrifice triggers
• Infinite surveil