Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Zack Fair, and Sifter of Skulls

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Zack Fair on the battlefield
• Sifter of Skulls on the battlefield
• available

Steps

1. Activate Zack by paying and sacrificing it
2. When Zack dies, its persist ability and Sifter of Skulls 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 Sifter of Skulls trigger, creating a 1/1 Eldrazi Scion creature token
5. Resolve the Zack ability from step 1
6. Activate the Eldrazi Scion by sacrificing it, adding
7. Repeat

Results

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