Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Shilgengar, Sire of Famine, and Butcher Ghoul

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Shilgengar, Sire of Famine on the battlefield
• Butcher Ghoul on the battlefield

Steps

1. Activate Shilgengar by sacrificing Butcher Ghoul When Butcher Ghoul dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
2. Resolve the Shilgengar ability
3. Activate Shilgengar by sacrificing Butcher Ghoul When Butcher Ghoul dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
4. Butcher Ghoul enters and dies as a state-based action due to having 0 toughness
5. Its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
6. Resolve the Shilgengar ability from step 4
7. Repeat from step 4

Results

• Infinite Blood tokens
• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers