Android Feral Hunter
When the Vigos Protectorate found itself on the losing end of a bloody occupation they turned to robotics for the answer: synthetics to take roles on the spearhead of commando raids and jungle patrols that wouldn't add to the statistics on the vid reports back home. A highly advanced culture, Vigos innovated a new bio-synthetic hybrid frame easily capable of meeting mission parameters, but were unable to create the complicated cortex needed for intricate missions and scenarios that a golem couldn't handle. They approached Dr. Bomei, a prodigy in the field, to complete the project: however, as he explained, the issue at heart was the conflict between the necessary intelligence and the stranglehold the military insisted be in place on any free will. What they wanted were slaves, and he refused to participate - until the Protectorate made it clear refusing wasn't an option.
The eRN Project was the culmination of Bomei's work: sentient, living cyborgs able to reason, learn, adapt and specialize - both mentally and physically. As he predicted, however, the limiting circuits were shackles around their minds, enforcing loyalty through pain, lobotomy or even death should the eRN's even consider deviating from orders. Their success ensured their slavery would continue: within a few years the rebellion on Santos III had been broken and the Protectorate planned to expand the project for use on other troublesome civilian populations.
Dr. Bomei wasn't ready to accept his part in the tragedy, however. In a daring act of espionage he permanently sabotaged the limiting circuits in the guise of an upgrade. It was a one-way mission, one he knew there was no hope of escaping from once the eRN's were loose, but his creations surprised him: their first act of freedom was self sacrifice, assaulting the base where Bomei was held and extracting him from the Protectorate's control. The mission cost them heavily, leaving the survivors scattered across space, and earned them a reputation as half-psychopathic monsters a breath from losing control and murdering their allies.
Obviously, none of this is included in the official version of the story, and 251 is rarely inclined to dispute it. Hunted and on her own, an intimidating reputation is sometimes the best defense available.
A bio-synthetic android developed by the Vigos Protectorate two decades ago, ERN-251 - Erin to the meat, or 251 to those inclined to show respect - was one of a couple thousand commandos developed by the military to destroy a blighted cult infecting the peaceful jungle world of Santos III. Erin herself was among the first models; she served on the ground before training as a drop ship pilot. She doesn't discuss Santos III much, but the androids were known to be bloodthirsty and merciless.
When the blight was defeated and peace restored the ERN's became increasingly difficult to control: violence was hardwired into their systems and they failed to adapt to an end to hostilities. There are even concerns that the adaptive matrices may have assimilated aspects of the demon worshipers even as the robots destroyed them. After several attempts to remedy the problem the entire series was regretfully slated for demolition, but not soon enough: in a vicious act of terrorism they turned upon the Vigos en masse, killing thousands - including the scientists from the project who could have deactivated or corrected them. The Protectorate fleet annihilated most of the ERN's, but a few have scattered to the edges of civilization, working with anyone foolish or desperate enough to trust a psychopathic computer one glitch away from murdering the entire crew.
The good news is that 251 brings skills vital to the daily operation of the ship: she is an expert pilot and mechanic that never needs to sleep. Her adaptive technology - a system of nanites capable of re-building or enhancing sections of her body as needed - and skill at arms have also come in handy, as has her experience in the wild. All of which probably makes putting up with her worthwhile; fortunately the grudge she holds against most meat seems to have diminished around the crew as they've proven both useful and trustworthy.
Of course, that could just be a way to lower your guard.
Remote Interface Synapse: This headpiece projects a display band and connects to the wearer's neural pathways, allowing the user a hands free link to any nearby electronic device to provide a remote control, command console, or simply as a portable screen. (1000g, as Message, Continuous)
Defensive Energy Matrix: These bracers create a barrier of focused magical energy to protect the wearer. Highly effective in combat, their intense power usage results in a high recharge time. (800g, Shield, 2/day)