Altar of Dementia + Karlov Watchdog + Switcheroo + Yarus, Roar of the Old Gods

RGWU identity

Commander legal

The 4 combo pieces

What must be in place

An opponent controls a creature.
You control a face-down creature whose front face is a permanent card.
You have enough mana to cast Switcheroo.

How to execute it

  1. Cast Switcheroo 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.

What the combo produces