Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Blasting Station, and Clockwork Hydra

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Blasting Station on the battlefield
• Clockwork Hydra on the battlefield

Steps

1. Activate Blasting Station by tapping it and sacrificing Clockwork Hydra
2. When Clockwork Hydra 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. When Clockwork Hydra enters, Blasting Station triggers, untapping Blasting Station
4. Resolve the Blasting Station ability
5. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite damage
• Infinite death triggers
• Infinite sacrifice triggers
• Infinite mana creatures you control can produce
• Infinite untap of creatures you control