The Arch Android
Physically an arch-android is usually indistinguishable from a standard surrogate type android. The things that make it a superior surrogate are entirely in the internal hardware, typically a vastly increased amount of internal data storage and processing power and a special signal interface system that prevents the arch android from being used as a conduit to hack the mainframe of the supercomputer intelligence controlling it. The majority of Arch-androids expand the basic abilities of the surrogate by having the unit outfitted with an Exo-cranial cyberdeck. The exo-cranial cyberdeck is a common, if unfashionable, extension of intercranial computer interface systems. Given the limited space inside a human skull and some personal issues with the artificial brain many people opt to have a few hard points added to their skull and pick up a hardware ring that sits around the back of their head. Normally this exo-cranial system is more memory, more slots for skillsofts, and safety gadgets like safety nets that prevent physical trauma from being force dumped from the CogNet, or biofeedback fuses to prevent harm from malware and cyber attacks. For the Arch Android, the exo-cranial cyberdeck is an expanded and augmented brain core for their personal surrogate/avatar.
Arcologies typically are controlled by a central LAISC, and are associated with the city that hosts the megastructure. The avatars of these machine intelligences are stylized to best represent the spirit of the arcology and the city it is in. Some examples include the LAISCs of the Chicago arcoplex all being either well dressed men in 1920s Gangster or Lawmen clothing, or female Flappers. There are 8 of them so there can be some variety. Likewise, the Atlanta LAISC appears as a southern belle, while the LAISC crew of Dallas appears ironically as cast members of the Petroldrama Dallas.
The AISC and LAISC are both fundamentally immobile structures, as their intellect is contained within a computer mainframe. The hardware required to host their minds is simply too large to be fitted to something as small as a tank, aircraft, or ridiculously, an android cranium. As the Human Surrogate program proved to be a success it wasn't long before the supercomputers decided to take a try at it. They had done mundane things like remote controlling droid vehicles like tanks and aircraft, but these were often rapid series of instructions sent to the LAI controlling the vehicle, and not true surrogacy.
The basic surrogate android had to undergo modifications, the main being a major upgrade of the core computer and data signal system. Simply put, a single AISC or LAISC intakes and crunches more data per second than a human mind is capable of. The second concern was for computer safety. Systems that run autonomous robots, be it computers running drones, or a human running a surrogate involuntarily make themselves vulnerable to cyber attack simply by running an open link between their home system and the drone being used. While hacking a surrogate user would net access to bank accounts and personal data, successfully hacking a control command computer's surrogate could get anything from control over an arcology, access to major bank information, or even access to serious military hardware and information. As such, the entire signal system was rebuilt from the ground up. The new architecture of the system dramatically limits access by simple mode of the signal itself, as it operates on a frequency that little hardware actually operates on. This gives the disadvantage of limited range, but few Arch Androids leave the arcology they inhabit, or the environs that house the artificial intelligence itself.
The first application of the arch android was a Public Service 'droid that served as a visible representation of the almighty computer that controlled everything. This mundane aspect showed that it was possible for a machine to use a surrogate, and that people were for the most part willing to accept the avatar form of the almighty computer. The public service droid also demonstrated the vulnerability of the system when the first models were hacked, the mainframes accessed and compromised and the drama that unfolded, such as the emergency evacuation of the San Diego arcology, the theft of 1.2 billion Federation credits from the Little Rock arcology, or the riots that ensued when hackers took control of the Newark Arcology and started messing with the internal transit system, water supplies, and the like. In each case, significant charges were filed, the PS surrogates were pulled, and several dozen people went to cryoprison.
A L/AISC is capable of handling several arch androids at a time,but seldom uses more than just the one. The others are usually reserved for back up or emergency use (if the main is damaged, out for repairs or upgrades, etc). The signal system can be used to access almost any device that is capable of wireless data use, regardless of its connection to the CogNet. that being said, if the controlling computer of an arch-android wanted to hack into someone's system, they could either do it through the arch android and it's remote signal, or through a CogNet based attack. Or both, usually both. Aside from instant access to everything the L/AISC has access to or knowledge of, most Arch-androids have no special abilities beyond a typical android or surrogate body. Almost all Arch-androids start as standard surrogates and each is custom modified from there.
There are custom builds that enhance the arch android for a specific purpose, such as more paramilitary minded version with armor plating and more robust construction. But the number of hulking tank bots bristling with guns is exactly 0. Bristling tank bots don't need constant guidance from a super computer, nor are they very adept at dealing with puny humans.
The Mysterious Benefactor: The PCs, a hardened cadre of shadow ops and mercenaries have been working for a mysterious benefactor for a while, and while it is obvious that the benefactor is using a surrogate (its not all that odd really) it's not obvious that the benefactor is a machine using another machine as a puppet. the curious issue is that the PCs have been actively working against the faction that the L/AISC is part of. Are the PCs being set up to take the fall as scapegoats, or is the L/AISC playing both sides against the middle? Great for paranoid players, because they could be used to undermine the computers opponents in its own faction, or be used to make the machine look more important.
More than Meets the Eye: The PCs are tasked with escorting a VIP to a meeting with a group of rebels, criminals, or otherwise dissidents. Unbeknownst to them, their VIP is an Arch-Android and when it arrives on the location it will use it's enhanced signal system to hack into every piece of electronic hardware the rebels have. The PCs, if they are mediators, will have facilitated the compromise of one side's entire computer network, and possible be responsible for their defeat. (Especially if the Arch Android is the avatar of a real d$%k of a AISC like Skynet, or the Architect ala the Matrix)
Meet Joe Black: The L/AISC has hobbies and interests, and perhaps one of these is in the purview of the PCs. The Arch-android is sent to interact with the PCs on a level where they do know they are dealing with a surrogate, but they have no idea that their new best friend is actually a 19 ton mainframe that enjoys having fetishistic sex, engaging in firefights with sewer mutants, or some other odd job. This could also be interesting if the L/AISC simply really dislikes or likes one of the PCs and has gone out of their way to do something to them, or for them.
Metropolis: If nothing else, the Arch Android is the voice and physical representation of one of man's greatest accomplishments. Nothing can add gravitas or seriousness to a situation quite like finding out that the contact you are meeting IS the city. Or having the Arch android in attendance means that whatever is going on is important enough that it warrants the attention of one of the most intelligent beings on the planet.