Adarkar Valkyrie, Intruder Alarm, and Bloodflow Connoisseur

Prerequisites

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

Steps

1. Activate Adarkar Valkyrie by tapping it, targeting Bloodflow Connoisseur
2. Activate Bloodflow Connoisseur by sacrificing it
3. When Bloodflow Connoisseur dies, Adarkar Valkyrie triggers, returning Bloodflow Connoisseur from your graveyard to the battlefield
4. When Bloodflow Connoisseur enters the battlefield, Intruder Alarm triggers, untapping all creatures
5. Resolve the Bloodflow Connoisseur ability
6. Repeat

Results

• Infinite LTB
• Infinite ETB
• Infinite sacrifice triggers
• Infinite death triggers
• Infinite untap of all creatures
• Infinite mana creatures you control can produce
• Infinite +1/+1 counters on Bloodflow Connoisseur