Adarkar Valkyrie, Intruder Alarm, and Shilgengar, Sire of Famine

Prerequisites

• Adarkar Valkyrie on the battlefield
• Intruder Alarm on the battlefield
• Shilgengar, Sire of Famine on the battlefield

Steps

1. Activate Adarkar Valkyrie by tapping it, targeting another creature you control
2. Activate Shilgengar by sacrificing the creature targeted in step 1
3. When the creature dies, Adarkar Valkyrie triggers, returning the sacrificed creature to the battlefield
4. When the creature enters the battlefield, Intruder Alarm triggers, untapping all creatures
5. Resolve the Shilgengar ability Repeat

Results

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