The Silverstari term for daemon, of which there are a multitude of varieties, but usually referring to those that originate from the Shadowlands.
Historical Oni (OOC)
Oni are creatures from Japanese folklore, variously translated as demons, devils, ogres or trolls. They are popular characters in Japanese art, literature and theatre.
Depictions of oni vary widely but usually portray them as hideous, gigantic, creatures with sharp claws, wild hair, and two long horns growing from their heads. They are humanoid for the most part, but occasionally, they are shown with unnatural features such as odd numbers of eyes or extra fingers and toes. Their skin may be any number of colors, but red and blue are particularly common.
They are often depicted wearing tiger-skin loincloths and carrying iron clubs, called Tetsubo. This image leads to the expression "oni with an iron club" (oni-ni-kanabō?), that is, to be invincible or undefeatable. It can also be used in the sense of "strong beyond strong", or having one's natural quality enhanced or supplemented by the use of some tool.
Some villages hold yearly ceremonies to drive away oni, particularly at the beginning of Spring. During the Setsubun festival, people throw soybeans outside their homes and shout "Oni wa soto! Fuku wa uchi!" ("Demons out! Luck in!"). Monkey statues are also thought to guard against oni, since the Japanese word for monkey, saru, is a homophone for the word for "leaving". In Japanese versions of the game tag, the player who is "it" is instead called the "oni".
Retrieved from http://en.wikipedia.org/wiki/Oni_(folklore)