Ubersoldaten

The "ubersoldaten" was an umbrella term to describe the genetically and cybernetically re-engineered young human super-soldiers that saw service during the Thousand Day War against the Ice Warriors.

The modifications included augmented nervous systems (which robbed the recipients of the ability to dream), increased strength, enhanced reflexes and spatial perceptions, all of which could be further boosted via specially designed combat drugs. However, the people undergoing these procedures were deliberately sterilised to prevent the biological and legal problems that would arise from passing on corporately-owned genetic sequences to their offspring.

Next Generation
In the years following the war, Imogen initiated the development of a second generation of ubersoldaten whose enhancements were entirely biological. These new ubersoldaten were designed to have lower baseline metabolic and oxygen requirements (manifesting in slowed breathing and heart rates) that would lead to coma-like conditions in ordinary humans. Further their physical and mental reflexes along with strength and endurance were intended to be heightened, and the appendix was made fully functional to allowing them to derive peak nutritional value from a wide variety of food stuffs, though as a trade off they would eat more frequently. The heart, liver and lungs were also designed to be larger than standard human organs, while the immune system was made to be significantly more robust and bone density was increased.

Aware of this project but unwilling to interfere directly, an individual likely to be a future incarnation of the Doctor made contact with the hacker known as the Angel Francine, a veteran of the Thousand Day War. Using her contacts amongst her fellow veterans, she arranged for an armed raid on the eugenics facility that destroyed the projects's physical infrastructure and research data archives. However, the raid revealed that a single prototype had already been created; rather than being euthanased, the newborn was instead adopted and raised as Kadiatu Lethbridge-Stewart. (PROSE: Transit)

Behind the scenes
The word Ubersoldaten is German and literally means "Oversoldiers", although in this context it is more likely to be translated as "Supersoldiers".