Mirrorpool + Splendid Reclamation + Troubled Healer + Horizon Explorer

Mirrorpool

Splendid Reclamation

Troubled Healer

Horizon Explorer

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 untapped due to Horizon Explorer.
7. Repeat from step 2.

This intricate engine transforms your graveyard and land base into a self-sustaining loop, powered by the incredible static advantage of Horizon Explorer ensuring your returned lands enter ready to use. You begin by casting Splendid Reclamation to set up your resources, using Troubled Healer as a convenient outlet to sacrifice your other lands down to just Mirrorpool. With the stage set, Mirrorpool sacrifices itself to copy that original Splendid Reclamation, allowing the copy to pull every single land back to the battlefield. Because Horizon Explorer makes all those lands enter untapped, you immediately have access to all your mana again to restart the process and repeat the entire sequence indefinitely.