Peregrine Drake, Cavern Harpy, and Panharmonicon

Prerequisites

• Peregrine Drake in hand
• Cavern Harpy in hand
• Panharmonicon on the battlefield
• available

Steps

1. Activate up to five lands you control by tapping them, adding at least
2. Cast Peregrine Drake by paying
3. Peregrine Drake enters the battlefield, triggering its ability twice
4. Resolve the first Peregrine Drake trigger, untapping the five lands
5. Activate the five lands by tapping them, adding at least
6. Resolve the second Peregrine Drake trigger, untapping the five lands
7. Cast Cavern Harpy by paying
8. Cavern Harpy enters the battlefield, triggering its ability twice, returning Cavern Harpy and Peregrine Drake from the battlefield to your hand
9. Repeat

Results

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