Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Viscera Seer, and Witch-king, Sky Scourge

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Viscera Seer on the battlefield
• Witch-king, Sky Scourge on the battlefield

Steps

1. Activate Viscera Seer by sacrificing Witch-king When Witch-king dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
2. Activate Viscera Seer by sacrificing Witch-king When Witch-king dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Resolve both Viscera Seer abilities from step 1 and 3
4. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers
• Infinite scry 1