Yarus, Roar of the Old Gods + Karlov Watchdog + Bloodflow Connoisseur + Bazaar Trader

Yarus, Roar of the Old Gods

Karlov Watchdog

Bloodflow Connoisseur

Bazaar Trader

How it works

1. Activate Bazaar Trader by tapping it, giving control of Karlov Watchdog to an opponent.
2. During the opponent's turn, activate Bloodflow Connoisseur 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 Bloodflow Connoisseur ability.
5. Repeat from step 2.

This clever setup hinges on a clever jurisdictional trick with Bazaar Trader: by gifting Karlov Watchdog to an opponent, you weaponize its static ability—which prevents permanents your opponents control from being turned face up during your turn—against your own board. With that restriction in place, whenever you use Bloodflow Connoisseur to sacrifice a face-down creature, Yarus, Roar of the Old Gods triggers to return that permanent to the battlefield face down, but Karlov Watchdog blocks it from ever turning face up. This traps the creature in an endless loop of dying and sneaking right back onto the battlefield, feeding Bloodflow Connoisseur infinite sacrifices and +1/+1 counters.