Mirrorpool + Splendid Reclamation + Zuran Orb + Archelos, Lagoon Mystic

Mirrorpool

Splendid Reclamation

Zuran Orb

Archelos, Lagoon Mystic

How it works

1. Cast Splendid Reclamation by paying 3.
2. Holding priority, activate any number of lands you control except Mirrorpool by tapping them, adding at least 2C.
3. Activate Zuran Orb by sacrificing a land other than Mirrorpool.
4. Repeat step 3 until Mirrorpool is the only land you control.
5. Activate Mirrorpool's second ability by paying 2C, tapping and sacrificing it, copying Splendid Reclamation.
6. Resolve the Splendid Reclamation copy, returning all land cards from your graveyard to the battlefield untapped due to Archelos.
7. Repeat from step 2.

This ingenious loop turns a graveyard into an infinite engine by feeding your lands to Zuran Orb to fuel Mirrorpool's creature-copying ability—which isn't even what's being copied here, as you instead use Mirrorpool to duplicate Splendid Reclamation! Each time the copied Splendid Reclamation resolves, it dumps every sacrificed land straight back onto the battlefield, instantly restocking your fuel supply for another cycle. The real genius that makes the math work without entering a tapped-out lag is Archelos, Lagoon Mystic, whose passive ability ensures that as long as it remains untapped, all those returning lands enter the battlefield completely untapped and ready to tap for mana again.