Railway Brawler + Crystalline Crawler + Meticulous Excavation

Railway Brawler

Crystalline Crawler

Meticulous Excavation

How it works

1. Cast Crystalline Crawler by paying 4, ensuring to spend at least three different colors of mana to cast it, causing Crystalline Crawler to enter the battlefield with at least three +1/+1 counters on it.
2. When Crystalline Crawler enters the battlefield, Railway Brawler triggers, putting four +1/+1 counters on it.
3. Activate Crystalline Crawler's first ability by removing all +1/+1 counters from it, adding and the remaining mana in any combination of color(s).
4. Activate Meticulous Excavation by paying 2, returning Crystalline Crawler to your hand from the battlefield.
5. Repeat.

This looping engine turns Crystalline Crawler into a self-sustaining mana factory by leveraging Railway Brawler's massive power-doubling entry trigger alongside Meticulous Excavation's repeatable bounce effect. When Crystalline Crawler enters the battlefield with enough initial counters to fuel its ability, Railway Brawler doubles down by dumping a flood of +1/+1 counters onto it, netting you a surplus of colored mana after paying the {2}{W} activation cost to return the Crawler to your hand. Because Meticulous Excavation lets you continuously bounce and recast the Crawler on your turn, you can repeat this cycle indefinitely to generate infinite colored mana, storm count, and creature triggers.