Yarus, Roar of the Old Gods, Karlov Watchdog, Altar of Dementia, and Fateful Handoff

Prerequisites

• Yarus, Roar of the Old Gods on the battlefield
• Karlov Watchdog on the battlefield
• Altar of Dementia on the battlefield
• Fateful Handoff in hand
• You control a face-down creature whose front face is a permanent card
• You have enough mana to cast Fateful Handoff

Steps

1. Cast Fateful Handoff by paying its mana cost, giving control of Karlov Watchdog to an opponent
2. During the opponent's turn, activate Altar of Dementia by sacrificing a face-down creature you control
3. When the creature dies, Yarus's second ability triggers, returning it from your graveyard to the battlefield face-down as a 2/2 creature, and then not turning it face-up due to Karlov Watchdog
4. Resolve the Altar of Dementia ability
5. Repeat from step 2

Results

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