Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Propeller Pioneer, and Hammerhead, Maggia Boss

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Propeller Pioneer on the battlefield
• Hammerhead, Maggia Boss on the battlefield

Steps

1. Activate Hammerhead by sacrificing Propeller Pioneer
2. When Propeller Pioneer dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it
3. When Propeller Pioneer enters, its fabricate ability triggers, putting a +1/+1 counter on it
4. Resolve the Hammerhead ability
5. Repeat

Results

• Infinite +1/+1 counters on a creature
• Infinite creature ETB
• Infinite creature LTB
• Infinite creature sacrifice triggers
• Infinite death triggers