Mikaeus, the Unhallowed, Umbral Collar Zealot, and Furystoke Giant

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Umbral Collar Zealot on the battlefield
• Furystoke Giant on the battlefield

Steps

1. Activate Umbral Collar Zealot 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 Umbral Collar Zealot ability
4. Activate Umbral Collar Zealot 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 Umbral Collar Zealot ability
7. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers
• Infinite surveil