Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Ashnod's Altar, and Evernight Shade

Prerequisites

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

Steps

1. Activate Ashnod's Altar by sacrificing Evernight Shade When Evernight Shade 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 Evernight Shade When Evernight Shade dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. Evernight Shade enters and dies as a state-based action due to having 0 toughness
4. Its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it
5. Repeat from step 3

Results

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