Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Krark-Clan Ironworks, and Thopter Squadron

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Krark-Clan Ironworks on the battlefield
• Thopter Squadron on the battlefield

Steps

1. Activate Krark-Clan Ironworks by sacrificing Thopter Squadron
2. When Thopter Squadron 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 Krark-Clan Ironworks ability
4. Repeat

Results

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