Kuruoshiki Oni (狂オシキ鬼) is a secret character in Super Street Fighter IV: Arcade Edition. Little is currently known about him. He is in fact, Gouki who has lost control of his power and is now an actual demon instead of a half demon, which confirms that he has transcended humanity.
NOTE: This character should not be mistaken as Shin Gouki. It should be noted, however, that in several pieces of artwork Kuruoshiki Oni is depicted with what appear to be glowing, orange beads around him.