Mephistopheles

Mephistopheles (メフィストフェレス) is a character in the Shaman King manga and anime series. He is one of the Four Kings of Hell, and the guardian of the Spirit of Wind.

About
An ancient King of Hell, Mephistopheles has the ability to grant people wishes, but at the cost of their souls. He will grant people wishes as he did with Faust I, but will often find a loophole in the contracts and take their souls before they expect it.

He is first mentioned having met with Johann Faust I by Faust I's descendant Johann Faust VIII during his fight with Asakura Yoh. Faust I wanted to gain every bit of knowledge in the world, so he summoned Mephistopheles and made a deal with him. He would trade his immortal soul for his services. Seeing the Shaman Fights as an opportunity to reach his goal, Faust entered the Grand Shaman Fight and lost. After this, Mephistopheles decided to make good on the deal and took Faust I's soul.

Patch Tribe originally managed Five Grand Elemental Spirits in a holy commune where spirits of the tribe would go after they die. However, the elemental spirits were too powerful to be controlled by human class spirits, and after the incident of Hao, Patch Tribe decided to entrust the elemental spirits to gods who rule respective hells. However, some gods such as Satan and Lucifer were considered to be inappropriate because they are "too famous" and "too powerful to be controlled by agreements", therefore Enma Daioh and Anubis and Izanami and Mephistopheles were chosen because of their personalities to respect agreements, and are "less known" and "less noticeable".

When Sati Saigan and Team "Myooh" went to Hell to steal the remaining four of the Grand Elemental Spirits, Kado fought against Mephistopheles in order to retrieve the Spirit of Wind. Despite losing his left arm, Kado ultimately defeated the King of Hell.

Anime/Manga Difference
He is never directly referred to in the 2001 anime series so he does not make an actual appearance.

Trivia

 * Despite his position as a "King of Hell", he is actually a major demon under Satan in most Judeo-Christian beliefs.