Umbral Collar Zealot, Thunderblust, and Hardened Academic

Prerequisites

• Umbral Collar Zealot on the battlefield
• Thunderblust on the battlefield
• Hardened Academic on the battlefield

Steps

1. Activate Umbral Collar Zealot by sacrificing Thunderblust
2. When Thunderblust 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 Thunderblust
4. Resolve the Umbral Collar Zealot ability
5. Repeat

Results

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