Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Ambitious Dragonborn, and Yahenni, Undying Partisan

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Ambitious Dragonborn on the battlefield
• Yahenni, Undying Partisan on the battlefield

Steps

1. Activate Yahenni by sacrificing Ambitious Dragonborn
2. When Ambitious Dragonborn dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to its replacement effect
3. Resolve the Yahenni ability
4. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite death triggers
• Infinite sacrifice triggers