Quandrix Command + Crystalline Crawler + Naru Meha, Master Wizard + The Earth Crystal

Quandrix Command

Crystalline Crawler

Naru Meha, Master Wizard

The Earth Crystal

How it works

1. Cast Quandrix Command by paying its mana cost, choosing its first and third modes.
2. Holding priority, cast Naru Meha by paying its mana cost.
3. When Naru Meha enters, it triggers, copying Quandrix Command, with the copy's first mode targeting Naru Meha and the copy's third mode targeting Crystalline Crawler.
4. Resolve the copy of Quandrix Command, returning Naru Meha from the battlefield to your hand and putting four +1/+1 counters on Crystalline Crawler due to The Earth Crystal.
5. Holding priority, activate Crystalline Crawler three times by removing four +1/+1 counters from it, adding 2.
6. Repeat from step 2.

This clever loop relies on Naru Meha, Master Wizard entering the battlefield with flash to perpetually copy Quandrix Command off the stack. While Quandrix Command bounces Naru Meha back to your hand for re-casting, its third mode simultaneously fuels Crystalline Crawler by dropping four +1/+1 counters onto it—a number doubled cleanly from two thanks to The Earth Crystal's replacement effect. You then cash in those newly minted counters by utilizing Crystalline Crawler's mana-producing ability to fund Naru Meha, Master Wizard all over again, generating infinite triggers while The Earth Crystal also helps smooth out your mana requirements elsewhere.