The core of being a face dancer is the mutable face. The technology is relatively simple, and only requires a scan of the face to be replicated and a medical grade polyforge. The new face is 'printed' out as a prosthetic, using an electrosensitive biopolymer. This is the sort of material that is commonly used to put synthetic skin over artificial limbs where growing real skin would be problematic. These compounds are not difficult to come by as they are commonly used by people with cybernetic augmentation.
The Face of a Face Dancer
Under the mask, a person who wishes to be a face dancer has to undergo a procedure where muscle tracer inlays have to be implanted in their face. Without these inlays, the mask being worn would look like a mask glued to their face. The muscle tracers relay electrical impulses to the mask, which the electrosensitive polymers respond to. Thus, the wearer smiles, and the mask smiles as well. This limits the number and scope of people who are willing or able to become face dancers.
Why not more? There is certainly a market for people who can in a few hours literally become another person, especially with a good ghost team behind them, keeping up the fake virtual presence as well. The facial work is the drawback. Once implanted, the tracers are tied into the facial and cranial nerves making removal painful and difficult. If done wrong, it can leave a person with facial paralysis or worse. Face dancers eventually lose their own facial expressions, as the material used can often amplify gestures, so a twitch of the lip is all that is required for a smile, while a normal smile on the wearer turns into a Nicholson Joker rictus on the mask. Long time users end up with a largely blank or neutral expression as they have spent countless hours cultivating their skill to use a fake face. In areas like law enforcement, there exists a certain level of trust that is still required, and police units that have employed on staff face dancers see a dramatically lower approval rating. The populace has accepted the wojek artificial cops, but when they see a human face in uniform, they need to believe who they are talking to is who they are talking to.
The Face Dancer is a mole, an infiltrator, and saboteur, making a living from imitating other people. There are two prominent groups of face dancers in the Cosmic Era, shadowrunners and low tier actors. Shadowrunners use face dancing as a way to hide their identity and ply their work as low profile operatives. Why launch a massive shadow war to steal files, when a good face dancer with a nice rack can put on a pretty face, saunter into the offices and get a job as an information technologist, and in a few weeks, oops her way into the mainframe, steal the data and then apologize to the boss for breaking the console. No muss, no fuss, and no one the wiser, until six months later when the aforementioned data is sold on the black market.
Low level actors and actresses have resorted to this technology to imitate more successful artists, ranging from working in porn parodies, to B and C grade level entertainment copies of popular media streams. There is significant legal action, as well as media based shadow ops to hunt down and eliminate this underground faction, to destroy their mask making operations, and so forth.
The spy community uses face dancers as well, but the biometric scanning and other identification technology used in sensitive areas can usually beat a face dancing mask. The mask only changes the appearance of the wearer's face. It doesn't change their voice (there are cybernetic implants that do, an Tracheal Vox will allow for extreme voice modification) nor does it change retinal patterns, or genetic/biometric data like gene scans, fingerprints, etc. These can all be be overcome through various methods such as artificial eyes, synthetic skin gloves, and so forth. The level of modification required to use these devices
Kroenen, the Faceless Man
The Faceless Man is a whisper in the spy community, a bad dream among the shadowrunner networks, and one of the most feared and hated people on the planet. Little is known about Kroenen, even the name is just one of the aliases adopted by the agent, even his gender is in question. What is none is that Kroenen is an extreme level cybernetically enhanced individual, and suspected of being a high level parapsychic as well. His body is presumably stripped down to the minimum, allowing for his to create elaborate disguises that include growing an organic outer shealth cultured from the DNA of the person he plans on imitating. He has extensive modifications, and a suspected modular body system, allowing him to exchange body parts as needed. Should a security system have a breath analyzer, he'll have cultured a set of lungs, if not, it's the gas respirator in his torso. Kroenen's mimicry seemingly knows no bounds, as he can as easily become a woman, a man, any race, and can appear as anything from the late teens into old age. Anyone could be Kroenen. The agent has extensive skills with firearms, melee weapons, improvised weaponry, demolitions, and an array of other skills. It is suspected that he has a cybernetically altered brain allowing him to chip-jack skills, so that he can can become an expert on any skill as needed by a job.
All these rumors are fine and dandy, and the Faceless Man should be a terrifying foe, but it leaves two questions that should be more worrisome. Who has provided the tech and bio support for the Faceless Man? That level of tech requires maintenance, and it is neither cheap, nor simple. Secondly, who employs the Faceless Man, and to what end?
Trick, Turn, and Prestige
Also known as the Magicians, the trio are a group of Face Dancers who make their living by doing high level infiltration. The trio will insinuate themselves into a community, agency, or corporation, typically moving into low level clerical or servitor jobs. While there they will lay out plans to hit the target they are after. They don't kill, don't carry out abductions, or cause collateral damage. Their specialty is data theft. Trick is androgynous, having moving to a genderless biology. This allows Trick to emulate men, women, or larger bodied children. Turn is an average sized man, but is a master of distraction and has a silver tongue. Prestige is an empath and psychic projector, and appears differently to anyone she meets. The trio are very good at what they do, and have a altruistic tradition of giving a large portion of their wealth to various charities and foundations that are commonly in need.
Author's Note: Face Dancers were inspired by a trio of sources, the mask wearing agents of Mission Impossible, the cult film Darkman, and the Face Dancers of the Dune universe. (There is also a band called the Face Dancers, so it seems the name isn't trademarked)