Sun Titan, Umbral Collar Zealot, and Unhallowed Pact

Prerequisites

• Sun Titan on the battlefield
• Umbral Collar Zealot on the battlefield
• Unhallowed Pact on the battlefield

Steps

1. Activate Umbral Collar Zealot by sacrificing Sun Titan
2. When Sun Titan dies, Unhallowed Pact triggers, returning Sun Titan from your graveyard to the battlefield
3. When Sun Titan enters, it triggers, returning Unhallowed Pact from your graveyard to the battlefield attached to Sun Titan
4. Resolve the Umbral Collar Zealot ability
5. Repeat

Results

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