Yarus, Roar of the Old Gods + Karlov Watchdog + Phyrexian Altar + Bazaar Trader

Prerequisites

• Bazaar Trader does not have summoning sickness.
• You control a face-down creature whose front face is a permanent card.

Steps

1. 1Activate Bazaar Trader by tapping it, giving control of Karlov Watchdog to an opponent.
2. 2During the opponent's turn, activate Phyrexian Altar by sacrificing a face-down creature you control, adding one mana of any color.
3. 3When 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. 4Repeat from step 2.

Effects

• Infinite colored mana
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers