Mysterious is the character you'll meet in the Dream Sequence, either by running out of Resurrector modules and completely dying, or when you complete the main campaign in any way. During your 'death', Mysterious is the only character within the Dream Sequence, by which his text prompt will explain that the moments before your death were only a glimpse of a future in which you failed to complete your mission, rendering these events as a non-existent parallel dimension to the storyline, once you re-spawn by entering the portal behind him.
Upon completing the main storyline, Mysterious will be joined by both Mentor and Rimanah in the Dream Sequence. He will explain to you that the actions you took during your playthrough wasn't the 'true' way of finding the truth about your existence and the game's plot itself. "You may have not followed the right path", and you'll have to be "reborn" again, by which passing into the portal behind him, restarts the whole story from the first mission, waking up in the cave.
In the post Cycle phase when you return to the temple and talk to the 3 E.Y.E members one of them will also claim to have dreams involving mysterious but quickly cut off. This is the only time Mysterious is directly referenced outside of the dream sequence.
- Mysterious wears Jian heavy armor, and should you attack him during the dream and lose, it will say that you were killed by a Jian. Aside from this he does not appear to belong to the Jian faction.
- There is only one NPC with an appearance similar to Mysterious, wielding the same staff; this NPC is Cilufer.
- The origins and motives of Mysterious aren't exactly clear, but he seems to act like a mystical guide to the player's journey of self-awareness within the game's universe.
- There is a statue built to resemble both Mysterious and Cilufer (the unique feature being their staff) outside of the Jian temple, seen during the Rimanah ending. This could either mean Cilufer and Mysterious are of much greater importance than the game shows, or simply coincidentally the only persons with a similar appearance to the statue.