Teysa, Orzhov Scion, Darkest Hour, and Altar of Dementia

Prerequisites

• Teysa, Orzhov Scion on the battlefield
• Darkest Hour on the battlefield
• Altar of Dementia on the battlefield
• An additional creature under your control

Steps

1. Sacrifice the additional creature to Altar of Dementia, milling target player 1
2. Because of Darkest Hour, the creature is black, and thus triggers Teysa's ability, creating a 1/1 black Spirit token
3. Sacrifice the token to Altar of Dementia, milling target player 1
4. Teysa's ability triggers again, creating another token

Results

• Infinite death triggers
• Infinite milll
• Infinite sacrifice triggers