Mikaeus, the Unhallowed, Soulstinger, and Umbral Collar Zealot

Prerequisites

• Mikaeus, the Unhallowed on the battlefield
• Soulstinger on the battlefield
• Umbral Collar Zealot on the battlefield

Steps

1. Activate Umbral Collar Zealot by sacrificing Soulstinger
2. When Soulstinger dies, its second and undying abilities trigger
3. Resolve the first trigger, allowing you to put a number of -1/-1 counters on a creature equal to the number that were on Soulstinger
4. Resolve the undying trigger, returning it from your graveyard to the battlefield with a +1/+1 counter on it
5. When Soulstinger enters the battlefield, its first ability triggers, putting two -1/-1 counters on it
6. Resolve the Umbral Collar Zealot ability Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite -1/-1 counters
• Infinite surveil 1