Myr Propagator + Umbral Mantle + Ashnod's Altar + Power Artifact

Myr Propagator

Umbral Mantle

Ashnod's Altar

Power Artifact

How it works

1. Activate Myr Propagator by paying 1 and tapping it, creating a token copy of itself.
2. Activate Ashnod's Altar by sacrificing the Myr Propagator token, adding CC.
3. Activate Myr Propagator by paying 1 and untapping it, giving itself +2/+2 until end of turn.
4. Repeat.

This brilliant engine relies on reducing activation costs to create an unstoppable loop of mechanical replication and sacrifice. By using Power Artifact to discount the untap ability of Umbral Mantle—which is equipped to Myr Propagator—you can infinitely untap the Myr for just one mana instead of three. Each time it untaps, you generate a token copy of the Myr Propagator, which you can immediately feed into Ashnod's Altar to yield the two colorless mana needed to sustain the loop while infinitely scaling the original creature's size.