Soul Foundry + Panharmonicon + Corridor Monitor + Peregrine Drake

Soul Foundry

Panharmonicon

Corridor Monitor

Peregrine Drake

How it works

1. Cast Soul Foundry by paying 4.
2. Soul Foundry enters the battlefield, triggering its imprint ability twice, exiling Peregrine Drake and Corridor Monitor.
3. Activate up to five lands you control by tapping them, adding at least 4.
4. Activate Soul Foundry by paying 7 and tapping it, creating a token copy of Peregrine Drake and Corridor Monitor.
5. The Peregrine Drake and Corridor Monitor tokens enter the battlefield, triggering their abilities twice.
6. Resolve both Corridor Monitor triggers, untapping Soul Foundry.
7. Resolve the first Peregrine Drake trigger, untapping up to five lands you control.
8. Activate up to five lands you control by tapping them, adding at least 4.
9. Resolve the second Peregrine Drake trigger, untapping up to five lands you control.
10. Repeat from step 3.