Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Zack Fair, and Skittering Precursor

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Zack Fair on the battlefield
• Skittering Precursor on the battlefield
• available

Steps

1. Activate Zack by paying and sacrificing it
2. When Zack dies, its persist ability and Skittering Precursor triggers
3. Resolve the persist trigger, returning Zack from your graveyard to the battlefield without a -1/-1 counter on it due to its replacement effect
4. Resolve the Skittering Precursor trigger, creating a 0/1 Eldrazi Spawn creature token
5. Resolve the Zack ability from step 1
6. Activate the Eldrazi Spawn by sacrificing it, adding
7. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers