Shilgengar, Sire of Famine, Safehold Elite, and Hardened Academic

Prerequisites

• Shilgengar, Sire of Famine on the battlefield
• Safehold Elite on the battlefield
• Hardened Academic on the battlefield

Steps

1. Activate Shilgengar by sacrificing Safehold Elite
2. When Safehold Elite dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Hardened Academic triggers, putting a +1/+1 counter on Safehold Elite
4. Resolve the Shilgengar ability
5. Repeat

Results

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