Levels of Nexus Initiation
Assisted Magical Interface
This is the lowest degree of actual initiation which can be undertaken to the Nexus. To achieve it, the candidate must have undertaken the magical training involved in communicating with the Core, and must be physically and mentally capable of assimilating the knowledge to be gained from the process (minimum Chaos in Psyche and Endurance). It cannot be undertaken by candidates who have only gained their interface with the Core through mechanical means, hence the Master's efforts (see History) only give access to the lower levels of the Core. The assisted initiation involves forming a link with a senior initiate of PIA rank or higher, who will guide the candidate through the Nexus itself. It imbues the candidate with instantaneous mental/magical communication with the Core, and the ability to operate the vehicles which can travel between Shadows and other Technocracy systems.
Advanced Assisted Magical Interface
This is the next stage of normal initiation, and requires a more detailed understanding of magic, and a higher physical capacity for assimilating the knowledge (minimum Chaos+5 in Psyche and Endurance). Access to information in the Core is quicker, and an AAMI can process and analyse information, rather than just retrieve it.
Prime Interface Assisted (PIA)
For PIA initiation, magical training is unnecessary (although that doesn't preclude magically trained interfaces from becoming PIAs), as part of the initiation process forces the specific knowledge of magical communication (but not a full magical education) into the mind of the candidate. However, it is a risky process, and is therefore rarely undertaken: if the candidate's mind or body are not strong enough to assimilate the information and knowledge received (minimum Amber in Psyche and Endurance), the candidate will either die, or go hopelessly and incurably insane. The initiation itself involves a link with the Prime Interface (ie Andrew), which temporarily transfers elements of the PI's physical nature to the candidate (à la assisted Pattern walking in the ADRPG) to enable them to be guided through the Nexus power itself with a reasonable chance of survival. It gives the PIA the equivalent of AAMI abilities, as well as some additional control over Nexus-based systems.
Basic Initiation
Basic initiation is the next step up from PIA initiation, and is only available to PIA initiates, or to direct descendents of the Prime Interface. As well as incorporating PIA abilities, the first level of initiation gives certain abilities comparable to Pattern or Logrus: defence; the ability to move through Shadow via 'edge walking', without the need for a vehicle; the ability to calculate and potentially affect the probabilities of certain things occurring; locating items in Shadow (although not specific items and people, ie you can find an unspecified army, but you can't find the Duke of Wellington); and permanent access to the Core's data stream for data retrieval and processing, etc.
Advanced Initiation
Advanced initiation is a further development of basic initiation. As well as incorporating all the basic abilities, it allows the initiate to: communication with and assisting others through the data stream; Hell ride (find a specific location very quickly); seek for specific people or items in Shadow (but not items of Power); remote scanning/far seeing - ie the initiate can look for something from a distance, although the range is restricted to within fifteen Shadow Veils of the initiate; instantaneous transport within fifteen Shadow Veils; and the ability to hold spells within the Nexus matrix to speed up the casting of them. Advanced initiates also have sensitivity to the use of other Powers, including areas which have been influenced by the Machine. Andrew's wife Niamh is believed to be an advanced initiate.
Exalted Initiation
This is the highest level of initiation which can be achieved within the Nexus. The Council of Twenty are exalted initiates, as well as Andrew's children with Niamh - Lucy, Jonathan and Abigail. There are no other known exalted initiates. The specific abilities it gives its initiates aren't clearly understood, but they appear to include: full clearance within the data stream; seeking items of Power; unlimited far sensing; and unlimited instantaneous transport. Exalted initiates are also reported to be able to affect an area around where they are located so that it is compatible with Technocracy technology, even if the Shadow they are on is not; and also to have the potential to exert control over lower level initiates.
The Master's Legacy
It is going to take a long time for the Prime Interface to restore the Technocracy, and communication with the core, to his original ideals. In the meantime, the methods pioneered by the Master of the Machine when he was within the Technocracy are still available, if discouraged, and there are many Technocracy Interfaces who still have to use these methods.
Mech Interface (MI)
A person who has received an electronic implant which will allow them to access the lower levels of the Central Data Core and other computer systems, without the ability to become an natural interface. When jacked in to a suitable terminal or device they can access and search for information, entertainment, etc. However, they are not a 'hacker' - they are reading, rather than changing what they see - and cannot defeat security protocols using this method.
Advanced Mech Interface (AMI) aka Librarians
An AMI has all the abilities of the MI, but in addition can influence the data - writing, as well as merely reading and searching - and can potentially interact with the underlying systems of the computer which they are accessing (as long as someone better didn't set them up). However, they are unlikely to be able to reach data beyond the middle security levels of the Core without assistance.
Mech Driver
As well as being able to function as an advanced mech interface, drivers have implants which allow them to jack into a Technocracy vehicle, and allows them to pilot the vehicle at its full potential, including the travel between Shadows.
Mech Engineer
The functions of the AMI are included at this level. In addition, engineers understand the technology to allow them to design and build Technocracy cross-Shadow engines. To do this requires specific components which are only found within the central ring of Technocracy Shadows.