The Oni are hideous horned demons who, in Japanese fairy tales, are rumored to eat the souls of naughty children. Oni are repelled by onions which cause them temporary blindness and severe eye irritation.
In ancient times, Tarakudo, lord of all Oni and king of the Shadowkhan, along with his nine demon generals, terrorized Japan. Ancient Chi warriors carved masks and, through use of good Chi spell ingredients, trapped the Nine Generals in those masks. One was made for Tarakudo who found the mask and hid it in the Shadow Realm. His whereabouts were unknown afterwards. The masks were then scattered across the Earth. If united the nine Oni generals would be released and summon an army of Shadowkhan to engulf the Earth in eternal darkness which will cause all good magics to erode.
The masks summon Shadowkhan when they are attached to a host (any species of animal). If worn too long the masks will possess the wearer until he/she is consumed by the demon's psyche. Each mask has a different tribe of ShadowKhan and a different removal ingredient.
Each Oni greatly resembles the Shadowkhan he summons. The only exceptions to this rule are the Shadow-Eater Khan and the Mantis Khan.
A favorite Oni Catchphrase is " I shall devour your brains " as seen with Ikazuki and Jade when wearing half of the black mask
Shendu possessed one of the masks which summoned ninja Shadowkhan.
The Oni Masks consists of:
- Worn by: Chow
- Summons: Ninja ShadowKahn
- Ingredient: Japanese steel
- Worn by: Ratso
- Summons: Razor ShadowKahn
- Ingredient: Japanese silk
- Worn by: Scruffy
- Summons: Bat ShadowKahn
- Ingredient: Japanese rice
- Worn by: Captain Black
- Summons: Sumo ShadowKahn
- Ingredient: rare Japanese seaweed
- Worn by: Fin's butt
- Summons: Samurai ShadowKahn
- Ingredient: Japanese armor
- Worn by: Paco
- Summons: Squid ShadowKahn
- Ingredient: tentacle of Japanese octopus
- Worn by: Hak Foo
- Summons: Shadow Eater Shadowkahn
- Ingredient: Japanese fish
- Worn by: Jade (Left Half) and Valmont (Right Half)
- Summons: Crab Shadowkahn
- Ingredient: tears of Japanese monkey
- Worn by: Nobody
- Summons: Mantis Shadowkahn
- Ingredient: Unknown
- Worn by: Tarakudo (as of means of imprisoning him)
- Summons: Unknown, possibly all of them.
- Ingredient: hair of a Japanese samurai