Kamen Oni: Mask Demon or Disguise Demon. (Hopefully that's right)
I guess this is my fan oni to the Ao Oni game. Unlike other onis though, I tried to have it look different and not just another recolour like other fan onis related to this game. (not saying they're bad, just something different would be nice.)
A little explanation of this oni.
This oni changes it's appearance depending on the last victims soul it took. In this case, this oni's last victim was a shrine maiden (miko 巫女). This oni attacks in two ways. 1). By chasing like the Ao Oni, or 2). someone mistakes it as a costume and puts the mask on. Once caught the mask will stick to the victims face. The victims soul then will be taken to a different dimension that looks similar to the natural world, but nothing is as it seems, as it is a puzzle. This dimension is a chance for the victim to escape if they succeed in solving the puzzle. If they do, the mask will drop from their face, and lay on the floor like a normal mask. (The oni will revive after a few moments so it's not suggested they take it home). If they fail, they become the new oni, and must find another soul, so theirs can leave to the afterlife. If a person is caught by the mask multiple times, the puzzles become harder and harder to solve.
Anyways~ Happy October~ Can't wait until Halloween~!