These warriors are bred but only one Black Codex member wasn't bred, Erex Solari Malren. They took these Taiidans and bio-engineered their DNA to create not only a more stable strand but also removed most of the mutations so that the drugs and enhancements wouldn't kill the Taiidan.
Top Xenobiologist created Neutronium/Duranium bones and joints for these soldiers so they would never have to fear their bones breaking, making thier bones nearly impossible to break as well as shock asorbing joints that are rated for starship bulkheads that allow them to move without breaking under intense gravititional stress the hardest part was making them small enough for a Taiidan body and skeletal system. These implants make the Taiidan's already 1700 pound body weigh in at 7000 pounds and with combat and battle adrenal implants they can be nearly unstoppable. Their armor isn't as heavy as it sounds but it is heavy enough to stop Taiidan Weapons to not harm them even then they can still fight even with intense pain.
Division 11 wanted to create a soldier that was even more perfect than they already had this idea lead to Project Black Codex. It was so top secret that only 5 people outside of the project know about it. Even in Division 11, these soldiers were created to be unstoppable weapons that don't die easily. They inserted specialized Nanites in them that regenerated their body from any damage but when they built their armor it was light armor by comparison, the soldiers weighed more than the armoring did only weighing 250 pounds, this neutronium armor by comparision is some of the strongest yet most flexible armor they ever designed.
While they grew their subjects only one survived the process without being grown Erex Solari Malren. Anyone who had knowledge of this project has been silenced if they were not part of the project, even the President of the UGI wasn't aware of them. However this was best turn out. Black Codex was a computer AI that monitored UGI frequencies and any transmissions throughout the Novan Galaxy, so when they chose a Name Project Black Codex many people wouldn't know that it was a super soldier program built on already super soldiers.