Shilgengar, Sire of Famine, Gravelgill Axeshark, and Hardened Academic

Prerequisites

• Shilgengar, Sire of Famine on the battlefield
• Gravelgill Axeshark on the battlefield
• Hardened Academic on the battlefield

Steps

1. Activate Shilgengar by sacrificing Gravelgill Axeshark
2. When Gravelgill Axeshark 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 Gravelgill Axeshark
4. Resolve the Shilgengar ability
5. Repeat

Results

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