Soul Foundry + Intruder Alarm + March of the Machines + Shield Sphere
How it works
- Activate Soul Foundry by paying 0 and tapping it, creating a token copy of Shield Sphere
- When the Shield Sphere token enters the battlefield, Intruder Alarm triggers, untapping all creatures.
- Repeat.
This ingenious loop turns a modest artifact into a self-sustaining engine by weaving together four very different pieces. March of the Machines is the catalyst that transforms our noncreature artifacts—including Soul Foundry and Shield Sphere—into artifact creatures, giving them the power and toughness they need to interact with the rest of the board. With that animation active, Soul Foundry can imprint Shield Sphere, whose zero mana value allows us to activate the Foundry's copy ability for free. Every time that token copy of Shield Sphere enters the battlefield, Intruder Alarm sees a new creature arrive and untaps all creatures, which conveniently includes our newly-minted artifact creatures and the Soul Foundry itself. This lets us immediately repeat the process to flood the board with infinite tokens, triggers, and untaps.