Mirrorpool + Splendid Reclamation + Trenching Steed + Horizon Explorer

Mirrorpool

Splendid Reclamation

Trenching Steed

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 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 Horizon Explorer.
7. Repeat from step 2.

This intricate loop transforms a single graveyard-fueled ritual into an endless cascade of returning lands by leaning on a clever engine of sacrifice and resurrection. With Horizon Explorer on the board to ensure your lands enter untapped, you begin by whittling your domain down via Trenching Steed until Mirrorpool stands alone as your sole remaining land. You then sacrifice Mirrorpool to its own second ability—fueled by the mana you floated beforehand—to copy the Splendid Reclamation you cast, which immediately floods your battlefield with every land currently resting in your graveyard. Because Horizon Explorer makes those returning lands enter untapped, you are free to tap them all for mana once again, re-engaging the Trenching Steed to clear the slate and repeating the entire process for infinite mana and landfall triggers.