Cyborg

Cyborgs are characters who have some parts of their body, or their entire body changed to cybernetic parts to improve their performance and abilities. This is done through a process commonly referred to as roboticization or automation.

Known Cyborgs

Canon

Sektor (unit LK-9T9): Was the first to undergo this process of automation, and he would prove to be their biggest success. The Lin Kuei programmed the cyborgs to do their bidding, and Sektor's main objective was to seek out and kill Sub-Zero, who left the clan after refusing to be transformed into a machine. Sektor was devoid of a soul, lost all human emotions, and has never succeeded in his mission.
Cyrax (unit LK-4D4): Was the second Lin Kuei warrior who was turned into a cyborg. However, Cyrax was captured by Sub-Zero, reprogrammed, and permanently malfunctioned. He was then found by Sonya Blade and Jax Briggs, and was partially returned to his human state. In gratitude, Cyrax joined the Special Forces.
Smoke (unit LK-7T2): Was the third and only member of the clan to be forcefully transformed into a cyborg against his will. After returning from a mission, he and Sub-Zero learned of the Lin Kuei's plans to transform their members into robots. The two fled; Sub-Zero escaped, but Smoke was captured and forced to become a cyborg. Although Sub-Zero was eventually able to help him rediscover his humanity and restore him to the side of good, he was later captured in Outworld by Shao Kahn's army. Hopelessly imprisoned, he chose to shut himself down. Afterwards, Smoke was found by Noob Saibot and reactivated, along with some tampering of his machinery. The two would form a team called Noob-Smoke. Smoke was torn between serving his new master and searching for his lost humanity. As of the Battle of Armageddon, he appears to have been once again restored to the side of good by Sub-Zero.
Sub-Zero (unit LK-52O): Replaced Smoke in Mortal Kombat (2011). In this timeline, Smoke was saved, and Sub-Zero was turned into a cyborg against his will instead. He regained his soul almost right after automation when he engaged Kabal in kombat, and helped the Earthrealm Warriors. He was later killed by Sindel, with his soul afterwards being one of the many claimed by Quan Chi, who later restored him to his human form after deeming technology unreliable. Unlike the other Cyborgs, Cyber Sub-Zero's blood is blue instead of black; there is no in-game explanation for why that is, but the assumption can be made that it is likely some kind of refrigerant.
Jax Briggs: When his arms were replaced with robotic ones after his original organic arms were torn off by Ermac, Jax became a cyborg, although he is not a cyborg ninja.
Kano: A Black Dragon criminal and mercenary, who has a metal plate over the right half of his face with a mechanical eye, capable of emitting laser beams.
Hsu Hao: A Red Dragon spy, who has a pulsating cybernetic implant that also enhances his strength instead of a heart.
Kabal: A Black Dragon criminal-turned-police officer, fitted with a cybernetic life support system after he was burned alive by Kintaro.
Triborg: A Lin Kuei cyborg, who can shapeshift into four other cyborgs; Sektor, Cyrax, Smoke and Cyber Sub-Zero. He seeks genocide to organic life forms.

Non-Canon

Hydro: He appeared in Mortal Kombat: Legacy, as a test presentation for Cyrax and Sektor. They completed their mission and killed him.

Unknown

Unit 5: A black cyborg ninja, but is essentially a darkened version of Cyrax. Yet when his armor is appropriated by Reptile, it is essentially a green version of Cyber Sub-Zero.

It has never been clear as to how mechanical the automations truly are. In Mortal Kombat 3, a damaged cyborg sparks and the skeleton is revealed. The skeleton is almost completely mechanical, aside from the rib cage and skull. The rest of the body is filled with odd mechanical parts and wires. This was about as complex as the cyborgs were at the time. In Mortal Kombat Gold, it was revealed that the cyborgs wore helmets and retained their faces underneath; Cyrax's alternate outfit and ending revealed this. His face had several implants on the eye and chin (which were removed in Mortal Kombat: Deadly Alliance). Although Cyrax claimed to be human again in his Gold ending, he is still clearly mechanical as demonstrated by his abilities in Deadly Alliance, although this could be merely a figure of speech referring to regaining his humanity. In Mortal Kombat: Deception, however, Smoke's appearance does not allow the possibility of retaining flesh. This is most likely due to being remodeled from the nanomachines in his body. Sektor's level of cyberization has never been elaborated on, although Cyrax's Armageddon ending implies that it is possible for him and Smoke to return to their human forms with the power of Blaze. The X-Ray Moves in Mortal Kombat (2011) reveal that the Lin Kuei cyborgs retain their biological skeleton and organs, although this is muddled by certain Cyborgs' brains being exposed from within their helmets after taking enough damage.

In Mortal Kombat: Tournament Edition, it is revealed that Sektor eventually creates his own clan of cybernetic warriors called the Tekunin. They are featured prominently in Mortal Kombat: Armageddon's Konquest mode, where Sektor captures the protagonist Taven and brings him aboard his Tekunin warship until later he and his clan were attacked by Sonya Blade and the Special Forces, thus enabled Taven to escaped his captors.

Jax replaced his arms with mechanical ones in Deception and after his bout with Ermac in MK (2011), whereas in the original timeline he simply wore cybernetic augmentations.

Behind the scenes

According to John Tobias, the cyberninjas started with John wanting to do a haunted armor, somebody else had the idea to making it a robot. Although wasn't convincing at first, the idea had an opportunity when John used the part about the Lin Kuei using advanced tech from the MKII official comic to tie the robots as assassins for the Lin Kuei. One of the inspirations of the entire Sektor/Cyrax subplot (a.k.a Cyber Initiative) was the Tinman from The Wizard of Oz. Instead of full robots, they were former human members from the Lin Kuei and, like the Tinman, they longed to be human again (like Cyrax and Smoke in the first timeline).^[1]

The outfits used for the cyborg ninjas in MK3 were actually a mix of BMX motocross gear, hockey protection, duct tape, and rubber tubing with some custom alterations made for the ninja part.^[2] The only completely original element used was the helmet itself. Jax's cybernetic arms were actually painted onto actor John Parrish to give them a more fluid, high tech feel.

Trivia

On June 22nd, 2011, the first Compatibility Pack for Mortal Kombat (2011) was released as a free DLC patch for those who are not yet able to purchase the new DLC character Skarlet. Included in this pack are the MK3 skins for Sektor and Cyrax, making these costumes the first free character-related DLC. Cyber Sub-Zero also later received a MK3 style costume with the Freddy Krueger compatibility pack, making him the only non-classic character to receive a Klassic Costume.
In every appearance they've made, the Lin Kuei Cyborgs bleed black fluid, supposidely oil, as opposed to red blood, with the exception of Cyber Sub-Zero in Mortal Kombat (2011).
In Mortal Kombat (2011), Sektor, Cyrax and Cyber Sub-Zero are the only cyborgs with unique color schemes and designs. Every other Lin Kuei Cyborg uses a grayscale version of Cyrax or Sektor's design; no generic cyborg with Cyber Sub-Zero's design is ever seen. The design of these generic Cyborg Lin Kuei are thematically similar to the invading cyborgs from Mortal Kombat Defenders of the Realm.
In Mortal Kombat (2011), although Sub-Zero replaces Smoke as the Lin Kuei Ninja automated against their will, Raiden briefly receives a vision showing Smoke being changed into a cyborg from the original timeline. In the vision, Cyber Smoke is represented by a grayscale Sektor, similar to the generic Lin Kuei cyborgs. However, John Vogel later acknowledged the cyborg frame used by Sub-Zero may in fact be the same frame used by Smoke in the original timeline. The design itself appears similar to Smoke's cyborg outfit in Mortal Kombat Deception and Mortal Kombat Armageddon.
By viewing the battle damage models, one can discover that the head and brain are still somewhat intact through the shell, although small cybernetic implants have been installed as well as their eyeballs being replaced by robotic ones.