Mirrorpool + Splendid Reclamation + Trenching Steed + The Wandering Minstrel

Mirrorpool

Splendid Reclamation

Trenching Steed

The Wandering Minstrel

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 Trenching Steed 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 The Wandering Minstrel.
7. Repeat from step 2.

This clever loop turns graveyard recycling into an engine by using Trenching Steed to prune away your lands until Mirrorpool is your sole remaining territory. You then cash in Mirrorpool to copy a cast Splendid Reclamation, which floods the battlefield with every land currently resting in your graveyard. Thanks to The Wandering Minstrel ensuring those returning lands enter untapped, your newly restored mana base can immediately pay for the next iteration while generating boundless triggers.