Mikaeus, the Unhallowed, Viscera Seer, and Twilight Shepherd

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Viscera Seer on the battlefield
• Twilight Shepherd on the battlefield

Steps

1. Activate Viscera Seer by sacrificing Twilight Shepherd
2. When Twilight Shepherd dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Resolve the Viscera Seer ability
4. Activate Viscera Seer by sacrificing Twilight Shepherd
5. When Twilight Shepherd dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
6. Resolve the Viscera Seer ability
7. Repeat

Results

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