The Machinist is a boss in the Act2. He allegedly built the city of Caldora and its robots, many of which were built in the likeness of his daughter Cynthia. Upon seeing the player's persona, he assumes he has been hunted down by a Brotherhood agent and attacks with a sword, which seems to be a curiously low-tech weapon for someone who allegedly has nanoscale mechatronics technology. Though completely unaware of the player's persona's goals, he has been tracking the persona's location via his/her possession of the Guardian robot.
The Machinist considers the Matron as having done some good things, but the Brotherhood disagrees with him and disagrees even more violently with his choice to build his creations; they consider his robots an abomination, though their apparent dislike for technology does not prevent them from having enough computing expertise to install a virus on the Machinist's server farms. The player's persona's battle with the Machinist is unique in that the Machinist's life is spared upon his defeat.
- What are you doing in my home?
- You'll never get through my nanomachines! (Attack doubled)
- More nanomachines! Mojima, I want more nanomachines! (Machinist is Bleeding out)
- My life's work--not yet complete--
- May have Translocation Meter, thorning
- Seem to be immune to normal 'stack' bleeding - like his machines. However in phase 3 he starts bleeding.