Heidar, Rimewind Master, Intruder Alarm, Dual Nature, Ashnod's Altar, and Memnite

Prerequisites

• Heidar, Rimewind Master on the battlefield
• Intruder Alarm on the battlefield
• Dual Nature on the battlefield
• Ashnod's Altar on the battlefield
• Memnite in hand
• Heidar does not have summoning sickness
• You control at least four snow permanents

Steps

1. Cast Memnite by paying
2. When Memnite enters the battlefield, Intruder Alarm and Dual Nature's first ability triggers
3. Resolve the Intruder Alarm trigger, untapping all creatures
4. Resolve the Dual Nature trigger, creating a token copy of Memnite
5. Activate Ashnod's Altar by sacrificing the Memnite token, adding
6. Activate Heidar by paying and tapping it, returning Memnite to your hand from the battlefield
7. Dual Nature's second ability triggers, exiling nothing
8. Repeat

Results

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