Oh-Oni

The Oh-Oni (大鬼 dai oni) is a fictional character in the manga series of Shaman King. It was created by Kyōyama Anna's uncontrollable Reishi (霊視) powers.

Appearance
A gigantic red Oni, it is by far the most humanoid Oni ever seen. It's torso is colored white with a pattern that resembles a demon-like face. It has horns and on its upper legs and upper arms is a spider web-like white pattern.

After it began feasting on other Oni and other spirits, it gained a thick mustache and a pointy collar.

Personality
Although almost calm when speaking, it is extremely sadistic and is far more intelligent than most Oni are. It refers to Anna as mom, since it was her who created it.

Abilities and Powers
As an Oni created from at least 1080 worries, hopes, and prayers, the Oh-Oni is very powerful. Matamune calls it's speed as great as an arrow and it's strength as strong as a hundred bulls.

Attacks


 * Oni-Daiko!: An attack that sends thousands of small Oni, from his cut down arm, to attack the opponent in a very violent way.

Osorezan Revoir
Basically the main villain of the story, appears when Anna is exposed to all the thoughts of the people around her as Yoh takes her out to celebrate the New Year's. This new Oh-Oni is far beyond the powers of Yoh to handle, and even Matamune, who arrives to help. Eventually, Matamune uses most of his Furyoku to impale the Oh-Oni's arm, but the Oh-Oni rips it off before Matamune can destroy him with Furyoku. Roaring in pain, the Oh-Oni grabs Anna and leaps to the very top of the mountain. There, he absorbs other spirits and other Oni to gain a mustache and a collar, as well as a regenerated arm. He is only defeated when Matamune sacrifices his form to unite with Yoh and grant him the last of his power. With Matamune's last bit of Furyoku, Yoh defeats the Oh-Oni, who also begins to lose corporeal form when Anna begins to love Yoh. He disappears, but not before making one last attack at his "mother" which Yoh deflects, and the Oh-Oni is sent to Hell.

Shaman Fights Second Round
The Oh-Oni makes a cameo when Yoh is sent to Hell by Lady Sati for training. The same Oh-Oni opens the gate of Hell for Yoh, welcoming him with a strangely calm and kind personality. He reveals he now serves Lady Sati for all eternity, and leads Yoh to his training area, where he leaves Yoh on his own. Before he leaves, the Oh-Oni smiles and asks Yoh to take care of his "mother".

Anime/Manga Difference
The Oh-Oni wasn't in the anime.

Trivia

 * The Oh-Oni's bakai bones was used, by Asakura Kino, to create the 1080 beads that Anna uses for her Itako rituals.