Darien, King of Kjeldor, Sanguinary Priest, and Altar of Dementia

Prerequisites

• Darien, King of Kjeldor on the battlefield
• Sanguinary Priest on the battlefield
• Altar of Dementia on the battlefield
• You control an additional creature

Steps

1. Sacrifice a creature to Altar of Dementia, targeting any player
2. Sanguinary Priest triggers, dealing 1 damage to you and gaining 1 life
3. Darien triggers, creating a 1/1 Soldier token
4. Resolve the Altar of Dementia ability, causing the targeted player to mill cards equal to the sacrificed creature's power
5. Repeat

Results

• Infinite death triggers
• Infinite ETB
• Infinite lifegain triggers
• Infinite LTB
• Infinite mill
• Infinite self-mill