The Mysterious Voice is an unknown character in the Mentality Fanfic Series, and has not made a physical appearance yet.
The Mysterious Voice has not made a physical appearance in the series, but is speculated to be revealed at some point.
The Mysterious Voice's identity is as of yet, unknown.
In Spirituality, the Mysterious Voice appears at the end of the finale, enigmatically mentions a "show" that is starting.
In Mentality, the Mysterious Voice first appears in the Bad End 3 Chapter, where Neisan has fallen through a vanishing step on a staircase, landing in a mysterious classroom. The classroom is oddly called, Despair Hotel, dispite the fact that its appearance is that of a school classroom. The Mysterious Voice begins psychologically torturing Neisan upon the laters' arrival, with a story of Despair. This was enough to almost completely break Neisan. A week later, the Mysterious Voice returns to Neisan and asks why he was still there. The Voice mentions students that will be arriving soon, but due to the fact that Despair Hotel is cutoff from all the other rooms, Neisan is unable to contact anyone. Because of this, Neisan breaks down completely.
The Mysterious Voice reappears in the Bad End 6 Chapter, where the group (including a different version of Neisan), falls down a trapdoor, into another room with no exit points. The Mysterious Voice then welcomes them, and explains where they are. When asked for the way out, the Mysterious Voice proclaims that noone is allowed to leave.