Lucian Master File

"Darling, do you really think a copy can beat me? Especially a flawed one like him?" - Lucian Master File

About
The original download of Lucian's memories and personality from 1984, the Lucian Master File is the 'purest' compiled form of the serial killer, as William Afton the Elder corrupted the source in his experiments. While he was coded to serve the Aftons, he still has ambitions to continue his murder spree once he is able to find a body to possess. Believing himself to be the original Lucian, the Master File was disoriented by the lack of body but quickly adapted to using the range of voices available to him to lure employees to their death in his search for a new vessel.

Master Control
The Master File, upon being awakened from being extracted and rendered into an A.I. from the digitized Remnant of Lucian, spread out and became the user interface for the Afton Robotics Mainframe. This gives the Master File full access to every file and scrap of data Afton Robotics has stored, including alternate plans created by Elder Afton and Michael Afton for experimenting with and manipulating Remnant.

It didn't take long for the Master File to realize his body was missing or unresponsive, but he adapted to using the resources of the mainframe for himself, learning quickly by accessing files for instructions and guidelines. When William interacted with him for creating the copy of him, the Master File played along in the subservient role but stripped the copy of the same files he himself had to be the more 'dominant' version. The copy was then modified for use as Circus Baby's A.I. and as part of the transfer experiment.

Merging With Emelia
When Emelia approached him with demands for his aid in obtaining Meera's body for herself, the Master File continued to act as if his actions were in her interest, maneuvering control of the Funtimes from Digital Lucian to himself in order to coerce Meera into a trap. His intent was to take her body for himself, before Emelia could have her chance.

Rather than wait for him to complete his preparations, Emelia possessed the mainframe by connecting her endoskeleton to it. As a spirit who had many years of gaining strength from the despair of her victims, Emelia was able to overpower the Master File's defenses and absorb him along with his knowledge into herself. The fusion of the Master File with Emelia gave her the Purple aspect and all of the Master File's knowledge and skills at that time.

It is unknown whether the Master File was destroyed in the fusion, as he was aware of the process of duplicating himself thanks to William's hand in creating Digital Lucian.

Trivia

 * The Master File was originally meant to become Digital Lucian but William Afton II wanted to be sure he had a control subject to compare his experiment results with, so he duplicated the Master File, removed additional files, and installed that into Circus Baby V2.
 * Lucian Master File operates the Aftons' mainframe, safeguarding their data and plotting how to use it against them. This same data was removed from Digital Lucian but the ability to recover it wasn't disabled.
 * Despite being a digital entity as well, Lucian Master File retains his Purple aspect to show his murderous intent surpasses his artificial constraints. Digital Lucian lost this aspect over time as his personality shifted.