Adrix and Nev, Twincasters + Myr Propagator + Krark-Clan Ironworks + Lightning Greaves

Adrix and Nev, Twincasters

Myr Propagator

Krark-Clan Ironworks

Lightning Greaves

How it works

1. Activate Lightning Greaves' equip ability by paying 0, attaching it to Myr Propagator.
2. Activate Myr Propagator by paying 3 and tapping it, creating two token copies of itself.
3. Activate Krark-Clan Ironworks twice by sacrificing the tapped Myr Propagator and a Myr Propagator token, adding CCCC.
4. Repeat.
5. Once you have infinite mana, you may forego sacrificing the Myr Propagator tokens.

This loop relies on the brilliant multiplier effect of Adrix and Nev, Twincasters, which doubles every token creature brought onto the battlefield. By paying to activate Myr Propagator while it's protected and granted haste by Lightning Greaves, you produce a flood of new token copies that are immediately fed into Krark-Clan Ironworks. Sacrificing those artifacts fuels the loop with more than enough colorless mana to sustain the process, ultimately letting you scale your token army to infinity.