The Librarious Maximus was built at the start of the Librarious project, which was started by the Watchmaker during the year 1 L.S.T. shortly after the completion of the Generator, from which it draws most of its power. It consists of a very large Culmination array linked to an incredibly powerful and sensitive detection system, all contained within an armored shell. Its purpose is to record every facet of every object, force, essence, and action within its range and store it within the array , to be preserved for a foreseeable eternity. It is a storage device that perfectly records the history of the surrounding space into a format that can be preserved and manipulated by users of Culmination.
What seperates it from other Librarious facilities is its capacity for information and the data management arrays built into its construction. All of the other facilities update to the master record of known space contained within the Maximus, allowing the Watchmaker to properly manipulate and catagorize the information the Legion has collected over its lifetime. This includes the master records of a beings existance, which are used to decide if a dead entity is worth being reconstructed to serve the Legion again.
The reason no other Librarious facilities of this size exist is the amount of power they consume in operation. Being close to the Generator, the Libararius Maximus is able to consume a massive amount of power to sustain itself. An amount of power so massive that even the Network has difficult transmitting it. So while multiple, smaller facilities are used throughout the galaxy, it is believed that there will never be a facility of such a magnitude ever constructed outside of the Coreworld.