Soul Foundry + Panharmonicon + Corridor Monitor + Great Whale

Soul Foundry

Panharmonicon

Corridor Monitor

Great Whale

How it works

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