Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Ashnod's Altar, and Hound of Griselbrand

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Ashnod's Altar on the battlefield
• Hound of Griselbrand on the battlefield

Steps

1. Activate Ashnod's Altar by sacrificing Hound of Griselbrand When Hound of Griselbrand dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
2. Activate Ashnod's Altar by sacrificing Hound of Griselbrand When Hound of Griselbrand dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite colorless mana
• Infinite death triggers
• Infinite sacrifice triggers