Myr Propagator + Umbral Mantle + Krark-Clan Ironworks + Biomancer's Familiar

Myr Propagator

Umbral Mantle

Krark-Clan Ironworks

Biomancer's Familiar

How it works

1. Activate Myr Propagator by paying 1 and tapping it, creating a token copy of itself.
2. Activate Krark-Clan Ironworks 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 clever loop turns the self-replicating machinery of Myr Propagator into an engine of endless creation and sacrifice. By equipping the creature with Umbral Mantle, you reduce its untap cost to just {1} thanks to the cost-reduction power of Biomancer's Familiar. Once the token copy is generated, Krark-Clan Ironworks steps in to recycle it for a quick influx of colorless mana, fueling the loop to churn out infinite sacrifice triggers, death triggers, and a massively oversized Myr Propagator.