Crystalline Crawler + Biogenic Upgrade + Reiterate

Crystalline Crawler

Biogenic Upgrade

Reiterate

How it works

1. Cast Biogenic Upgrade by paying 4, targeting Crystalline Crawler.
2. Holding priority, cast Reiterate with buyback by paying 4, creating a copy of Biogenic Upgrade targeting Crystalline Crawler and returning Reiterate to your hand.
3. Resolve the copy of Biogenic Upgrade, putting three +1/+1 counters on Crystalline Crawler and then doubling the number of +1/+1 counters on Crystalline Crawler.
4. Activate Crystalline Crawler's first ability six times by removing six +1/+1 counters from it, adding 4.
5. Repeat from step 2.
6. Once you have infinite mana, you may instead target other creatures using Biogenic Upgrade.

This clever loop turns Crystalline Crawler into a self-sustaining mana engine by leaning on its ability to both produce mana from its counters and tap to grow them. Biogenic Upgrade acts as the growth catalyst, scaling the counter count dramatically before Reiterate steps in to copy it over and over. By paying Reiterate's buyback cost with the mana harvested directly from Crystalline Crawler, you loop the entire process endlessly, generating infinite colored mana and pumping your board full of infinite +1/+1 counters.