An oni with blue skin, or occasionally with some other form of blue color scheme. Often depicted alongside a red oni, typically with humorously contrasting personalities. In such cases, the blue oni tends to be cooler and more cynical, while the red oni tends to be more hot-blooded.
A horror free game by noprops is named after this oni.
For the game use Ao_oni tag, and for the monster in the game use The_Oni_(ao_oni).
This tag implicates oni (learn more).