Myr Welder + Encroaching Mycosynth + Empowered Autogenerator + Duergar Mine-Captain

Myr Welder

Encroaching Mycosynth

Empowered Autogenerator

Duergar Mine-Captain

How it works

1. Activate Myr Welder using Empowered Autogenerator's ability by tapping it, putting a charge counter on Myr Welder and adding or for each charge counter on Myr Welder.
2. Activate Myr Welder using Duergar Mine-Captain's ability by paying 1R/W and untapping it, giving attacking creatures +1/+0 until end of turn.
3. Repeat.

This delightful little engine transforms Myr Welder into a self-sustaining mana and pump factory by leveraging Encroaching Mycosynth to turn everything in your graveyard into a valid target for its imprint ability. Once you exile Empowered Autogenerator and Duergar Mine-Captain with Myr Welder, the Mycosynth ensures the Welder is itself an artifact capable of gaining all of their activated abilities. You can then tap the Myr Welder to accumulate charge counters and generate escalating amounts of colored mana, using a portion of that bounty to pay Duergar Mine-Captain's hybrid cost and untap the Welder for another iteration.