Umbral Collar Zealot, Hardened Academic, and Persistent Constrictor

Prerequisites

• Umbral Collar Zealot on the battlefield
• Hardened Academic on the battlefield
• Persistent Constrictor on the battlefield

Steps

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

Results

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