Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Extruder, and Arcbound Tracker

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Extruder on the battlefield
• Arcbound Tracker on the battlefield

Steps

1. Activate Extruder by sacrificing Arcbound Tracker
2. When Arcbound Tracker dies, its modular ability and persist ability trigger
3. Resolve the modular trigger, putting Arcbound Tracker's +1/+1 counters on another artifact creature
4. Resolve the persist trigger, returning Arcbound Tracker from your graveyard to the battlefield
5. It will not have a -1/-1 counter on it due to its modular ability
6. Resolve the Extruder ability
7. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite +1/+1 counters