Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight, Intruder Alarm, and Hoverguard Sweepers

Prerequisites

• Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight on the battlefield
• Intruder Alarm on the battlefield
• Hoverguard Sweepers in hand

Steps

1. Cast Hoverguard Sweepers by paying its mana cost reduced by the number of creatures you can tap while casting it
2. When Hoverguard Sweepers enters, it and Intruder Alarm trigger
3. Resolve the Hoverguard Sweepers trigger, returning it from the battlefield to your hand
4. Resolve the Intruder Alarm trigger, untapping all creatures
5. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite storm count
• Infinite mana creatures you control can produce
• Infinite untap of creatures
• Return any number of creatures to their owners' hands