Collectors
Living beyond the Omega-4 mass relay in the Terminus Systems, the mysterious Collector species is glimpsed so rarely as to be taken for a myth by most in galactic society. In reality, Collectors are human-sized insectoid bipeds and can resemble massive winged beetles. They are a terrifying force in the galaxy, responsible for the murder of hundreds of thousands.
Collectors generate permanent stasis fields around themselves, creating nightmarish red-shifted energy fields. In battle, they hold position whenever possible, relying on their aggressive biotics and nearly limitless power. Several types of bipedal Collectors have been identified, including minions, defenders, zealots, assassins, and artillery-operators.
Acting together, Collectors have imprisoned entire cities in stasis. While no definitive forensic accounting exists to explain the fate of those imprisoned, leading speculation is that victims are harvested for scientific experimentation and neuro-biological repurposing.
Collector General
Cerberus xenobiologists believed until recently that the Collectors were coordinated by a biologically active caste, similar to other insectoid alien species. New evidence suggests the Collectors have a singular commander, a so-called "Collector General" that has never been seen on the battlefield. Instead, it selects its minions as remote platforms for its consciousness in a process that has been likened to a biological hack or a cybernetic version of demonic possession.
The Collector General can send a secure signal to any one of its minions, smoothly take control of their motor functions, and awaken their previously dormant biotic potential. In a matter of seconds, even the lowliest Collector drone can be upgraded to a battle-hardened biotic commander. If the Collector dies, the General can simply activate and control another body.
Postmortem analysis reveals that this "command signal" relies on cybernetic implants directly installed in the Collectors' cerebellums, but how the technology functions is presently unknown. Coordinating sensory input and motor functions simultaneous with remotely amplifying biotic abilities is beyond the grasp of current human science. Why such an advanced species would be interested in humans is puzzling. More disturbing still, victims of the Collectors say the General has spoken to them and referred to itself by a human name: Harbinger.
Harbinger
While monitoring outgoing transmissions sent by the mysterious leader of the Collectors to his minions on the battlefield, Cerberus intelligence experts also intercepted incoming transmissions. The signals were encrypted commands sent to the Collector General from a source outside the galaxy. This directing intelligence is likely the Reaper that refers to itself as “Harbinger.”
This indicates that the Collector General, previously thought of as a puppeteer-like figure, was essentially a mere conduit through which Harbinger mobilized the Collectors’ mission to protect and nurture an embryonic Reaper by providing it a steady supply of humans. In this way, the Collectors allowed the proto-Reaper to incorporate the human genome into its own construction, though why a Reaper would want such a thing is still unclear.
Oculi
An oculus is a mechanical servitor of the Collectors, apparently built with a single purpose -- to find and eliminate threats. Its outer structure has three apertures that house long-range detection equipment similar to those found on deep-space probes, used to find and track targets from near-stellar distances. Contragrav mass effect fields allow an oculus to move easily through space or atmosphere in pursuit of its prey, and a large central lens serves as the emission center for its weapons platform. All four of its lenses have a titanium iris covering that prevents the detector's optics from scratching due to interstellar dust or atmospheric residue.
Upon its destruction, more of the oculus' features become apparent. Its interior houses fibers of near-inorganic nerves, indicating that a Collector drone has been stripped down to its central nervous system, reinforced with interfacial gel that can withstand hard vacuum, and repurposed to pilot the oculus for the rest of its existence.
The central weapon is a strange one, operating on alien principles. It appears to use mass effect fields and directed energy to attack the strong nuclear force that holds its targets' atoms together, producing heat and light in an air atmosphere and causing irradiating gamma particles to burst from any heavy metals targeted by the beam. Such a weapon could easily cut through shields, and leave its target dying with just a glancing hit.