Mikaeus, the Unhallowed, Shilgengar, Sire of Famine, and Furystoke Giant

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Shilgengar, Sire of Famine on the battlefield
• Furystoke Giant 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. Resolve the Shilgengar ability
4. Activate Shilgengar by sacrificing Furystoke Giant
5. When Furystoke Giant dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
6. Resolve the Shilgengar ability
7. Repeat

Results

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