Atamagaokashii is an insane Anti-Toa. He was last seen escaping from the asylum that once held him. He has the strange ability to absorb victims' souls, then turn into an exact copy of them. (These are pictures of his true form.) His mask power allows him to corrupt the mind of any inteligent being, and make it as insane as him. You can never tell if he's planning to decapitate you or hug you. That's just how insane he is.
Looks menacing, doesn't he?
The chains that used to restrain him are now his weapons.
How we found the guard after Atamagaokashii had left.