Adarkar Valkyrie, Intruder Alarm, and Thermopod

Prerequisites

• Adarkar Valkyrie on the battlefield
• Intruder Alarm on the battlefield
• Thermopod on the battlefield
• Adarkar Valkyrie does not have summoning sickness

Steps

1. Activate Adarkar Valkyrie by tapping it, targeting Thermopod
2. Activate Thermopod's second ability by sacrificing it, adding
3. When Thermopod dies, Adarkar Valkyrie triggers, returning Thermopod from your graveyard to the battlefield
4. When Thermopod enters the battlefield, Intruder Alarm triggers, untapping all creatures
5. Repeat

Results

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