Derevi, Empyrial Tactician + Bloom Tender + Delney, Streetwise Lookout + Phantom Train

Derevi, Empyrial Tactician

Bloom Tender

Delney, Streetwise Lookout

Phantom Train

How it works

1. Activate Bloom Tender by tapping it, adding at least .
2. Activate Phantom Train by sacrificing Derevi.
3. Choose to return Derevi from your graveyard to the command zone.
4. Resolve the Phantom Train ability
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 Bloom Tender.
8. Activate Bloom Tender by tapping it, adding at least .
9. Resolve the second Derevi trigger, untapping Bloom Tender.
10. Repeat.

This loop turns Derevi, Empyrial Tactician into an easily recastable engine by leveraging Phantom Train as a sacrifice outlet that also grows with +1/+1 counters. Because Derevi costs a flat activation fee from the command zone rather than scaling with commander tax, you can loop its entry repeatedly. Delney, Streetwise Lookout acts as a vital multiplier here, doubling Derevi's enters-the-battlefield trigger so you get two untaps for each iteration. Finally, Bloom Tender provides the necessary colored mana engine to fund Derevi's return while generating infinite mana of any color your permanents can produce.