Rei

Rei is a former member of "The Enforcers," a mercenary law enforcement organization composed of identical-looking cyborg soldiers bearing only number designations instead of names.  To the public, they're considered the operation that ultimately outmoded traditional police (and police-affiliated androids) around two decades ago, as their sheer numbers, organized military training, and willingness to be hired by anyone made them much more appealing to the common man.  Soon enough the capital-E Enforcer business was on every street corner in every major city, promising that their farmed, cybernetically enhanced, and properly programmed clones would give consistent results every time.

In actuality, the Enforcers' clones are just empty shells, as growing a fully functional, adult body quickly in a lab just isn't feasible.  In order to "activate" them, brains are used from disenfranchised and marginalized human beings, often unwanted children.  In this new life, they're given a heavy set of implants and modifications in order to make them obedient and homogenous, forgetting their past identity.  With the designation μ-435-763, Rei diligently obeyed whomever needed the Enforcer brand of brutality that week, but eventually a niggling feeling started to grow in the back of their still-very-human mind.  Quelling several peaceful protests and incidentially learning more thoroughly about the injustices of the present day are what tipped them to the breaking point.  During a confrontation with PHANTOM and Future Sound, they had a breakdown, and left the crowd of Enforcers in a panic.  One Enforcer behaving unusually could go relatively undetected in a firefight...but the otherwise third-party, local thief Azriel Fletcher happened to be there as well, and their psionic brain implant noticed the storm brewing in Rei's head.

Azriel followed after Rei with the intent of helping them out, knowing all too well about the ghastly trade secret of the Enforcers' "recruitment" process.  After a brief confrontation (as Rei was all too ready to assume anyone stalking them would be doing so with ill intent), Azriel introduced them to Kaduceus, who surgically disrupted the tracking and brainwashing implements the Enforcers utilize.  Afterward, they helped them figure out their new name, and brought them to Marshal, another contact, this time a specialist in cybernetics.  Azriel was fine moving from place to place, but if Rei also had nowhere else to go, they needed a more permanent place of residence.  Marshal helped the duo get a shabby home downtown, and also hired Rei to help out in his scrapyard.  Not only was Rei now their own person, but also, having backup with Enforcer-level tactical knowledge and combat prowess certainly couldn't hurt Azriel's criminal schemes.  Nowadays, Rei is enthusiastic and sociable, with a thirst for knowledge of all kinds.  In a way, they're getting to be a kid again, though not without the occasional scuffle.  Though any serious altercations tend to bring their combat training to the front, Azriel helps them calm down afterward, considering them something of a sibling figure.