Thu

First appears in volume 0, next to Ie. Not much in him doing anything but he is an unknown just like everyone else. Thu is knowingly the only unknown that can't be understand as he only appears from time to time with no clear reason why he did it.

Power
Its believed that he as the power of immortal as he feels no pain. Not to be mistaken with immortality he can die from his spirit or still be held as prisoner.