Yedora, Grave Gardener + Phyrexian Altar + Urborg, Tomb of Yawgmoth + Kormus Bell

Yedora, Grave Gardener

Phyrexian Altar

Urborg, Tomb of Yawgmoth

Kormus Bell

How it works

1. Activate Phyrexian Altar by sacrificing another nontoken creature you control, adding one mana of any color.
2. When the creature dies, Yedora triggers, returning the creature from your graveyard to the battlefield face down as a Forest land and as a 1/1 Swamp creature due to Kormus Bell and Urborg.
3. Repeat.

This clever loop turns your entire land base into a self-sustaining mana engine by turning your forests and swamps into creatures and back again. Urborg, Tomb of Yawgmoth ensures every land on your board is a Swamp, which Kormus Bell immediately transforms into 1/1 creatures in addition to being lands. Once these land-creatures hit the graveyard, Yedora, Grave Gardener steps in to resurrect them face-down as fresh Forest lands, which instantly regain their creature status via Kormus Bell and Urborg so you can feed them right back into Phyrexian Altar for infinite colored mana, death triggers, and sacrifices.