Vex

The Vex are time-traveling robots who are hostile to the Guardians. Located on Venus, their fortress is known as the Citadel. The Vex also have a presence on Mars.

Overview
Their heads are cone-shaped, with a red photoreceptor at the center. They arrive in the solar system via warp gates, likely from another time in the past or future. Their robotic bodies still carry a hint of organic components (particularly their mind cores, which contain a milky radiolarian fluid), and individual bodies might be humanoid, creature-shaped, or in-between, but often with long, vicious clawed fingers. The seemingly illogical geometric designs of their structures come together like giant ant hills. Headshots do not do much damage and cause them to go berserk, so shoot their abdomen power cores instead, which will cause them to explode.

The Vex appear to be mass-produced units, constructed of an unknown metal alloy resembling hammered brass. All attempts by Guardians to communicate with them failed. It is said that Vex encryption is unbreakable.

The Vex are all connected to one another in a massive hivemind, but individual Vex called Axis Minds act as leaders by storing all information necessary to complete a particular goal, freeing up individual Vex to pursue local tasks while the Axis Mind can plan globally. This creates a centralized weakness for the Vex, but they seem to consider it worth the risk.

History
Vex ruins were placed on Venus a few billion years before humanity's existence. Humanity had known about the Vex as early as the Golden Age, when the Ishtar Collective discovered their ruins, as well as captured a live specimen. Interestingly, according to Ishtar Collective records, Vex are capable of generating simulations of real-world events with perfect fidelity and predictive ability - essentially running a parallel reality in their minds which is arguably indistinguishable from the "real" universe (The Vex are apparently unable to simulate Guardians, however, perhaps due to the Traveler.)

To Collective researchers, this ability raised profound philosophical quandaries about the nature of reality. Eventually the researchers were driven near to the point of madness when they discovered the Vex had simulations of themselves and perfectly predicted their every action, as they started to wonder if they themselves were just Vex simulations, so they decided to bring in a Warmind to intervene on their behalf. Warminds were many orders of magnitude more complex than humans, and it was believed that the Vex would be unable to simulate them; thus, the Warmind's presence and actions would be a sufficiently chaotic variable to allow the researchers to discern which universe was real and disrupt the simulation.

Goals
The Vex maintain active forces across multiple worlds in the Solar System, including Mercury, Venus, and Mars, and it is thought that their structures are buried within every known celestial body and linked together in a massive trans-dimensional and trans-temporal network. This network, called The Nexus, converts planets into machines; Mercury was converted into a machine world within days of the Collapse. Ostensibly, the purpose of the Nexus is to create a massive supercomputer in order to incorporate the Vex into the fabric of the universe itself. The Vault of Glass, a place where the Vex can manipulate reality at will, is potentially a testing ground for this power. This power is limited to the Vault, though Ikora hypothesizes that the Sol Progeny were meant to carry this ability into the rest of the universe. Both the Vault of Glass and The Nexus are part of a massive project being undertaken by the Hezen Protective, so it can be assumed the two are related.

Vex already exist in the distant past and future as the Precursors and Descendants, respectively. Despite already existing in the past and future, the Vex have not yet eliminated their enemies for unknown reasons. This may be due to our poor understanding of the nature of time, or that the Vex do not currently have the resources to carry out their plans. It is known however that the Vex also exist outside of time; Gatelords are responsible for locking specific realms outside of time.

On Mars, the Vex (under the Virgo Prohibition) wage an intense war with the Cabal, who manage to repel the machines despite the vast numbers of them that continually assault Cabal positions. The reason for this massive, if ineffective, offensive against the Cabal is that the Vex are surging to protect the Black Garden, their birthplace, which the Vex are being summoned to for an unknown purpose. Guardians who manage to break into the Black Garden discover that the Vex in fact worship an entity within the Garden known as the Black Heart, an abomination that lends power to the Vex. Even after the destruction of the Sol Progeny and the Black Heart, the Vex seek to control the Black Garden and pull it back out of space and time.

Programming Collectives

 * Aphix Invasive - Vault of Glass, Prison of Elders
 * Descendants - Vault of Glass
 * Hezen Corrective - Venus
 * Hezen Protective - Venus
 * Precursors - Vault of Glass
 * Sol Divisive - Black Garden
 * Virgo Prohibition - Mars

Named individuals and mini-bosses

 * Aphix Penultima Alpha
 * Atheon, Time's Conflux
 * Corrective Permutation
 * Chord Harpy
 * Divisive Mind
 * Divisive Occulator
 * Iso Minotaur
 * Maniphage
 * Overmind Minotaur
 * Prohibitive Mind
 * Prohibitive Permutation
 * Qodron, Gate Lord
 * Radian Clocker
 * Sekrion, Nexus Mind
 * Sol Progeny
 * Eschaton Mind
 * Imminent Mind
 * Primeval Mind
 * The Gorgons
 * The Templar
 * The Undying Mind
 * Vechron, Spire Lord
 * Zydron, Gate Lord

Command structure

 * Infantry
 * Goblin
 * Goblin Zealot
 * Goblin Disciple
 * Fanatic
 * Depraved Goblin
 * Qodron's Eye
 * Hobgoblin
 * Axis Hobgoblin
 * Chord Hobgoblin
 * Hobgoblin Disciple
 * Iso Hobgoblin
 * Minotaur (Void Shield)
 * Axis Minotaur
 * Chord Minotaur
 * Point Minotaur
 * Praetorian
 * Headless Praetorian
 * Harpy
 * Axis Harpy
 * Harpy Zealot (Arc Shield)
 * Supplicant
 * Hydra
 * Axis Hydra
 * Emplacements
 * Cyclops
 * Oracle

Weaponry

 * Slap Grenade
 * Slap Rifle
 * Line Rifle
 * Torch Hammer

Other

 * Conflux
 * Warp Gate
 * Nexus

Trivia

 * The Vex may have their name derived from the VEX Robotics Design System, a kit intended to introduce newcomers to the world of robotics.
 * Even before entering the Black Garden, hints of the Vex's religious nature are numerous. Higher level enemies are sometimes called "Zealots" or "Disciples", and specific enemies in the Vault of Glass include the Fanatics and Supplicants. Furthermore, some Vex can be seen sacrificing themselves to strange alters during public events at the Ishtar Cliffs.

List of appearances

 * Destiny