Hullbreaker Horror, and Intruder Alarm

Prerequisites

• Hullbreaker Horror on the battlefield
• Intruder Alarm on the battlefield

Steps

1. Activate any number of creatures you control by tapping them, adding an amount of mana
2. Cast the creature from your hand by paying its mana cost
3. Hullbreaker Horror triggers, returning another creature from the battlefield to your hand
4. Resolve the creature spell
5. When it enters, Intruder Alarm triggers, untapping all creatures
6. Repeat

Results

• Infinite ETB
• Infinite LTB
• Infinite mana creatures you control can produce
• Infinite storm count
• Infinite untap of creatures