Umbral Collar Zealot, River Kelpie, and Hardened Academic

Prerequisites

• Umbral Collar Zealot on the battlefield
• River Kelpie on the battlefield
• Hardened Academic on the battlefield

Steps

1. Activate Umbral Collar Zealot by sacrificing River Kelpie
2. When River Kelpie dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Hardened Academic and River Kelpie trigger
4. Resolve the Hardened Academic trigger, putting a +1/+1 counter on River Kelpie
5. Resolve the River Kelpie trigger, causing you to draw a card
6. Resolve the Umbral Collar Zealot ability Repeat

Results

• Infinite card draw
• Infinite draw triggers
• Near-infinite ETB
• Near-infinite LTB
• Near-infinite death triggers
• Near-infinite sacrifice triggers
• Near-infinite surveil