Vex

The Vex are ancient metal warriors, linked together and governed by Axis Minds. Unlike most species, they don't understand hostility, as the species had a common threat on their planet. As a result, what the beings found in the Solar System perceive as hostility is in reality simply the vex attempting to convert everything into something that makes sense to them.

Biography and Morphology
The Vex originated from before the beginning of the universe as highly tenacious patterns fleeing destruction at the battle fought outside of cause and effect. In the earliest epochs of the universe, the Vex existed as patterns in the primordial chaos, and later during the era of atomic matter rode comets down to young worlds and encoded themselves as a substrate of Radiolaria. From these primordial origins the Vex began to spread. The Vex appeared on Venus from an unknown location by way of transfer gates that allow them to instantly warp through worlds and time. All attempts to communicate with the Vex have failed, due to their single purpose to expand their species throughout the galaxy, commanded by Axis Minds that single-handedly control whole armies.

Their bodies are made of an unknown metal alloy resembling hammered brass,  yet they are not entirely mechanical; some organic materials are present as well. If they are decapitated, they will remain active and become more aggressive. Their routines and ceremonies remain mysterious and illogical to humans; they are hostile, unrelenting, and deadly. The Vex despise the Cabal as much as humanity and are constantly fighting them on Mars, keeping Cabal operations from expanding further into the system.

Bungie has described the Vex as having a "fascinating" fiction behind them, "which, in turn, creates one of the coolest deaths in the game."

Geography
The Vex have total control of Mercury and Nessus and inhabit a massive stronghold on Venus humans call The Citadel. They have a stronghold on Io which Asher Mir calls the Pyramidion. They also have a presence on Mars and are the sole residents of the Black Garden.

Goblin


Goblins are ground infantry and basic foot soldiers that defeat their enemies by overwhelming them in huge numbers.

Hobgoblin
Hobgoblins resemble Goblins, but are larger and can be distinguished by their distinctive tails, as well as differently shaped heads. Though Hobgoblins have relatively low health they should not be taken lightly due to the sniper-like line rifle they use. When shot, Hobgoblins will crouch, activating a temporary, impenetrable shield that deals solar damage to Guardians that get too close. This ability has a cooldown period.

Minotaur
Minotaurs are even larger than Hobgoblins, with broad shoulders and three glowing eyes. They are very dangerous if not handled quickly, due to their aggressive teleportation and explosive weaponry. They also have a Void shield.

Praetorian
Praetorians are a stronger, more devastating variation of Minotaurs who defend the entrance of the Vault of Glass. It would be foolish for a Guardian to engage these enemies alone.

Cyclops


Cyclops are large, T-shaped, one-eyed Vex. The Cyclops are known for being one of the strongest if not the strongest non-boss Vex unit. They function as a stationary turret of sorts, and do not appear often.

Hydra


Hydras resemble "robotic centipedes" and float through the air to attack from turrets attached to each segment of their wriggling bodies. They possess a large rotating shield.

Harpy
Harpies are smaller Vex that dart in and out of battle, firing from mouths filled with filaments. Though relatively weak, this unit relies on swarm tactics to overwhelm its foes. Harpies in missions that have the epic modifier active will possess an Arc shield.

Precursors
Vex precursors are found in a strike called "The Undying Mind" on Mars (destiny) they are white and have a lot more health than normal Vex enemies. Some goblin precursors have no head and are meant to surprise the players.

Wyverns
Wyverns are the newest addition to the Vex. They are found on Europa (destiny 2). They have a very distinctive design with a large metal front held up by two long legs and many light blue tales coming off of their back and a single red eye in the middle. They are notoriously hard to kill. Their radiolarian core rotates to make it harder to shoot and if you leave them too long, they jump into the air and launch at you. They also have a jab attack with multiple metal spikes and guns whose bullets spread out the further they travel.

Vex Programmings
Currently, eight programmings within the Vex army exist. These include:

Aphix Invasive
Little is known about the Aphix Invasive as units of this type are rarely encountered by Guardian forces. Units of this collective include Fanatics and Supplicants, both of which can be found in the Vault of Glass. The collective also includes several Axis Minotaurs who also appear in Public Events, with one such Minotaur appearing in The Nexus Strike. They also appear in the Prison of Elders.

Sol Imminent
The Sol Imminent (a.k.a. Descendants) are an ancient programming located in Venus, who have been seen in the darkest, deepest portions of the Vault of Glass.

According to multiple Ghost analysis, these Vex are extremely old, in that they have been active for an incalculable span of time—indicating that they may very well have come from the future. Gorgons are also members of this collective.[2]

Following the death of Dominus Ghaul, they began to gather on Mercury alongside the Precursors, in order to unite under Panoptes, Infinite Mind

Hezen Corrective
The Hezen Corrective is a programming located on Venus, with the primary objective of seeking out and destroying the House of Winter, a faction of the Fallen army. They are plain bronze.

Hezen Protective
The Hezen Protective is a programming located on Venus, with the primary objective of defending the Vault of Glass and the Endless Steps. They are gold with white stripes.

Sol Divisive
The Sol Divisive is a programming located in the Black Garden, most of which are frozen in rapture. Very few members of the group are active, but the ones that are very religious, due to the word "disciple" appearing in their names. They are green with moss hanging from their bodies.

Sol Primeval
The Sol Primeval (a.k.a Precursors) is a programming located inside of Venus. They are found within the Vault of Glass, where they fight along side the final boss, Atheon, Time's Conflux.

Sol Progeny
The Sol Progeny is a programming located in the Black Garden. This group consists of three massive Vex, who are designated as the protectors of the Black Heart. They resemble giant Minotaurs, with each bearing a differently-shaped head.

Virgo Prohibition
The Virgo Prohibition is a programming located on Venus and Mars, who are major enemies of the Cabal in the Meridian Bay area, as well as the protectors of the Black Garden's door. They are portrayed in blue and black.

Nonaligned:

 * Atheon, Time's Conflux
 * Sekrion, Nexus Mind
 * Zydron, Gate Lord
 * The Templar
 * Vekron, the Conductive Mind
 * The Undying Mind
 * Panoptes, Infinite Mind

Hezen Corrective:

 * Corrective Mind

Virgo Prohibitive:

 * Prohibitive Mind

Sol Divisive:

 * Divisive Mind

Sol Progeny:

 * Eschaton Mind
 * Imminent Mind
 * Primeval Mind

Battle Tactics and Technology
For the Vex, their battles are all about overwhelming numbers and massive armies. Little else is known about their battle tactics, but players should remember that the Vex weak spot is not the head (like with most enemies and for players) but rather the center of their torso, where their glowing power core is vulnerable. Decapitating them can actually make them more dangerous, as they enter a berserk state and fire wildly. However, pushing Vex into their berserk state could be beneficial as they lose some abilities: e.g. a headless Minotaur loses its shield, a headless Goblin loses the ability to teleport, and a headless Hobgoblin loses the ability to become immune and deal AoE damage for a short amount of time.

Trivia

 * The Vex are designed to resemble a "classic science-fiction machine race" mixed with the "inscrutable motives of a timeworn Lovecraftian nightmare monster." The result is not a typical science-fiction android race, but rather a "mixture of robots and creatures" that fight their enemies with "endless waves of metal armies."
 * Despite their appearance, the Vex are not robots--they are actually a heavily modified organic race that the player's Ghost claims to be radiolaria. This is also why destroying their heads simply enrages them--their organic, thinking parts are the white fluid that sprays from their power cores.