Derevi, Empyrial Tactician + Faeburrow Elder + Delney, Streetwise Lookout + Altar of Dementia

Derevi, Empyrial Tactician

Faeburrow Elder

Delney, Streetwise Lookout

Altar of Dementia

How it works

1. Activate Faeburrow Elder by tapping it, adding at least .
2. Activate Altar of Dementia by sacrificing Derevi.
3. Choose to return Derevi from your graveyard to the command zone.
4. Resolve the Altar of Dementia ability, causing target player to mill cards equal to Derevi's power.
5. Activate Derevi by paying 1, putting it from the command zone onto the battlefield.
6. When Derevi enters the battlefield, it triggers twice.
7. Resolve the first trigger, untapping Faeburrow Elder.
8. Activate Faeburrow Elder by tapping it, adding at least .
9. Resolve the second Derevi trigger, untapping Faeburrow Elder.
10. Repeat.
11. Once you have infinite mana, you may untap any other permanent(s) using Derevi.

This delightful loop transforms Faeburrow Elder into a powerhouse mana generator by leveraging Derevi, Empyrial Tactician's unique ability to bypass the command zone tax while providing multiple untap triggers. Thanks to Delney, Streetwise Lookout doubling Derevi's entry trigger, a single activation yields two untaps for the Elder—leaving you with a surplus of mana after recasting Derevi from the command zone. Finally, Altar of Dementia acts as the grim engine that feeds Derevi back into the command zone while continuously milling out your opponents with every sacrifice.