Transhuman

Broadly speaking, transhumans (pejoratively skinjobs, skinners, needlebrains) are individuals who have undergone biomechanical modification.

Overview
Human enhancement was fully realized under Combine rule in the form of the Overwatch Transhuman Arm, an elite supersoldier program. Transhuman bio-technology found applications in other areas of life, such as maintenance and engineering, but the primary focus of transhuman research remained firmly rooted in military fields.

The Liberation saw a dissemination of bio-technology into civilian populations, but few use the term transhuman to describe modified individuals. For all intents and purposes, the term transhuman refers to biomechanically enhanced models produced by the Combine and its remnants.

Generation Zero
Generation Zero, or Gen-0, refers to the first wave of transhumans produced by the Combine during the early years of the Overwatch program. Gen-0 transhumans lack the tissue mods found in later models, instead sporting a suite of biomechanical enhancements. Their augmentations brought enhanced strength and durability, but also necessitated extensive life support systems as they were intrusive and toxic. Most Gen-0s required large, bulky protective suits equipped with respiratory devices and were required to eat carefully designed nutrient pastes.

Gen-0 enhancements varied in design and application and were strictly mechanical. Many Combine historians are hesitant to classify Gen-0s as fully transhuman and instead view them as a 'prototype' generation.

Gen-0s are thought to be extinct.

Generation One
Generation One, or Gen-1, encapsulates the bulk of the Transhuman Arm's fighting force that existed during the stable years of the Occupation. Gen-1 models featured a robust, standardized set of enhancements that included increased strength and durability, greater reflexes, resilience to pain, and immunity to infectious diseases. The stomachs, livers, heart, lungs, and eyes of Gen-1s were also replaced with synthetic counterparts. The stomachs in particular required a specialized nutrient paste to be ingested through a gastrointestinal port; Gen-1s could not digest normal food.

To ensure loyalty, Gen-1 transhumans were subjected to intense brainwashing procedures. These procedures usually began with a light form of lobotomy and were sustained with "memory replacement" devices, which utilized hypnosis and emotional suppressants. The absence of desertion or disobedience within the Gen-1 ranks can be owed to the effectiveness of their brainwashing, but Gen-1s were known to develop psychosis if left without memory replacements for longer than one month.

Gen-1s are mostly extinct. As of 50 AL, rumors abound of soldiers surviving in stasis in hidden bunkers.

Generation Two
With the passing of the Liberation came a frantic wave of advancements in Overwatch's transhuman department. Gen-2 transhumans were quickly assembled after the Uprising in an attempt to increase longevity, which Gen-1s notably lacked. Gen-2 models are superficially identical to Gen-1s, with the most obvious additions being a more stable form of brainwashing and the ability to ingest food and water orally. Gen-1s and Gen-2s were often mixed throughout units, though the latter outlasted the former by a wide margin. Gen-2s are mostly extinct, with many active models decommissioned or repurposed by Combine remnants. The small number who defected went on to establish the Transhuman Underground.

Generation Three
By 5 AL, the remnants of the Combine had been pushed back into the Arctic Circle. No longer able to rely on overwhelming firepower, Overwatch adopted tactics of infiltration and sabotage to cripple their enemies. To this end, Generation Three transhumans were designed to be far less conspicuous in appearance. While Gen-1 and Gen-2 models could be easily identified by their sickly complexions and absences of body hair, Gen-3s can blend in with human crowds.

The Gen-3 creation process is what sets it apart the most from previous generations. Formerly, transhumanization required that a human candidate be surgically modified, then conditioned mentally. Gen-3s are not made from human candidates and are instead grown synthetically, progressing rapidly through infancy and childhood while in incubation.

Gen-3 plants are rumored to still live in Japan. Many defectors are part of the Transhuman Underground.

Generation Four
By 20 AL, conflict in the Arctic Circle had abated. Combine remnants regrouped in secure facilities near the North Pole, munitions all but depleted, while Liberation forces focused on reconstruction elsewhere. During this stillness, scientists in the Arctic began designing a new model of transhuman. Gen-4s, like Gen-3s, are grown synthetically. Unlike Gen-3s, they are assembled and grown as adults and have memory implants inserted early in gestation.

Gen-4 models are bestowed with synthetic muscle fibers and nerve cells to maximize strength, resilience, and reaction time. They are usually sent on assassination missions. There have been no reported instances of defection.

Reaction
Transhumans saw unanimous hostility from humans after the fall of the Union. Except for Psi, transhumans are considered criminals in all states and are ruthlessly hunted by vigilantes and Harvesters.

Following the November Riots, a group of Gen-3 and Gen-2 transhumans were offered pardons on the condition that they join the newly-formed Reclamation Authority as Harvesters.