Underworld Breach, Altar of Dementia, and Cathodion

Prerequisites

• Underworld Breach on the battlefield
• Altar of Dementia on the battlefield
• Cathodion on the battlefield

Steps

1. Activate Altar of Dementia by sacrificing Cathodion
2. Cathodion triggers, adding
3. Resolve the Altar of Dementia ability, causing yourself to mill cards equal to Cathodion's power
4. Cast Cathodion from your graveyard for its escape cost by paying and exiling three cards from your graveyard
5. Repeat

Results

• Infinite self-mill
• Near-infinite death triggers
• Near-infinite ETB
• Near-infinite LTB
• Near-infinite sacrifice triggers
• Near-infinite storm count