Shilgengar, Sire of Famine, Twilight Shepherd, and Thran Vigil

Prerequisites

• Shilgengar, Sire of Famine on the battlefield
• Twilight Shepherd on the battlefield
• Thran Vigil on the battlefield

Steps

1. Activate Shilgengar 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. Thran Vigil triggers, putting a +1/+1 counter on Twilight Shepherd
4. Resolve the Shilgengar ability
5. Repeat

Results

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