Gyre Engineer + Umbral Mantle + Heartstone

Gyre Engineer

Umbral Mantle

Heartstone

How it works

1. Activate Gyre Engineer by tapping it, adding .
2. Activate Gyre Engineer by paying 2 and untapping it, giving itself +2/+2 until end of turn.
3. Repeat.

This brilliant three-card loop relies on the mana-generating prowess of Gyre Engineer and the untap mechanics of Umbral Mantle to generate infinite power, all while Heartstone provides a crucial discount that makes the entire sequence work. Normally, Umbral Mantle's untap ability costs three mana, but Heartstone steps in to reduce that activation cost to just two, allowing the Engineer's generated {G}{U} to fully cover the cost to untap itself. Because the untap ability also adds a +2/+2 bonus each time, repeating this process indefinitely leaves you with an infinitely large creature to swing for the win.