Great Spirit

The Great Spirit(G.S.) is the Strongest of all the spirits and in the English Anime it was called King of Spirits

About
The Great Spirit is the oldest and most powerful spirit on the planet. It is nothing more than a shapeless mass of trillions of spirit interconnected. All lifeforms no matter how big or small comes from and end up back inside it. The power of this spirit is so immense that most normal people cannot even look at it without fainting. Only one person the "Shaman King" can even touch and control this spirit.

History
The Great Spirit is guarded by the Patch Tribe for eternity. They are the ones that find a worthy shaman to wield the Great Spirit's power by hosting the Shaman Fights every five hundred years, when the Destiny Star shows itself. The Great Spirit past was a difficult one. Fifteen hundred years ago the Shaman King created a big volcanic eruption that kill one-third of earth's population.

The Great Spirit is now resting and awaits it's new owner. The current Shaman King and the enheritor of the Great Spirit is Asakura Hao.

Anime/Manga Difference
In the anime the Great Spirit was worried that Hao might get him. The Great spirit had the power to transfer any feelings it had to the surrounding area which it did with the Patch and the remaining shamans. Hao succeeded in gaining the Great Spirit and had the Spirit of Fire eat some of it. Asakura Hao was eventually cut in half by Asakura Yoh and killed ending the fight and dissolving the oversoul Patch Village. The Great Spirit was freed from Hao and the Destiny Star that announces the Shaman Fight comes again and the fight starts all over again.