Machine God's Effigy + Horseshoe Crab + Mesmeric Orb

Machine God's Effigy

Horseshoe Crab

Mesmeric Orb

How it works

1. Cast Machine God's Effigy by paying 4, choosing to have it enter the battlefield as a copy of Horseshoe Crab that is an artifact.
2. Activate Machine God's Effigy by tapping it, adding .
3. Activate Machine God's Effigy by paying , untapping it.
4. Mesemeric Orb triggers, causing you to mill a card.
5. Repeat from step 2.

By utilizing Machine God's Effigy as a clever artifact copy of Horseshoe Crab, you bypass creature-summoning sickness while retaining the original's active untap capability, all while generating blue mana in the process. Each time you spend that mana to untap your modified crab, the passive presence of Mesmeric Orb notices the permanent untapping and forces you to mill a card. This creates a self-sustaining loop that continually mills your entire library down to the very last card.