Yarus, Roar of the Old Gods + Karlov Watchdog + Yahenni, Undying Partisan + Coveted Falcon

Yarus, Roar of the Old Gods

Karlov Watchdog

Yahenni, Undying Partisan

Coveted Falcon

How it works

1. Activate Coveted Falcon by paying 1, turning it face up.
2. Coveted Falcon triggers, causing an opponent to gain control of Karlov Watchdog and causing you to draw a card.
3. During the opponent's turn, activate Yahenni by sacrificing a face-down creature you control.
4. 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.
5. Resolve the Yahenni ability.
6. Repeat from step 3.

This intricate loop revolves around the clever manipulation of face-down permanents, using Coveted Falcon's disguise ability and face-up trigger to hand off Karlov Watchdog to an opponent. Because Karlov Watchdog prevents permanents your opponents control from being turned face up during your turn, Yarus, Roar of the Old Gods exploits this restriction: whenever you sacrifice a face-down creature to power up Yahenni, Undying Partisan, Yarus brings that creature right back to the battlefield face down—and keeps it locked in that state. This creates an endless cycle of leaves-the-battlefield, enters-the-battlefield, and death triggers that endlessly fuels Yahenni's growth and keeps your engine running.