Mirrorpool + Splendid Reclamation + Tiller Engine + Troubled Healer

Mirrorpool

Splendid Reclamation

Tiller Engine

Troubled Healer

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 Troubled Healer 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 tapped.
7. When the lands enter, Tiller Engine triggers that many times, untapping the lands.
8. Repeat from step 2.

This clever loop uses Troubled Healer to painstakingly trim your land count down until Mirrorpool stands completely alone as the last land on your battlefield. Once the stage is set, you cast Splendid Reclamation to dredge up your entire graveyard of sacrificed lands, letting Tiller Engine's triggers untap every single one of them as they reenter. With your lands fresh and ready for action, Mirrorpool steps in to copy the original Splendid Reclamation, perpetuating a relentless cycle that floods the board with infinite landfall and mana.