Shilgengar, Sire of Famine, Furystoke Giant, and Hardened Academic

Prerequisites

• Shilgengar, Sire of Famine on the battlefield
• Furystoke Giant on the battlefield
• Hardened Academic on the battlefield

Steps

1. Activate Shilgengar by sacrificing Furystoke Giant
2. When Furystoke Giant 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 Furystoke Giant
4. Resolve the Shilgengar ability
5. Repeat

Results

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