The Phalanx are techno-organic beings, who's nervous systems are composed of organic circuitry. Their body's are structured like machinery and the entire race has a single collective consciousness. They infect people with the transmode virus which converts them into the Phalanx collective. This evil race was born when scientist experimented on the remains of the New Mutant Warlock, who is a member of the Technarchy, a society of techno-organic beings. Technarchs feed by using the transmode virus to convert organic life forms into Phalanx and then draining their life away. The Phalanx construct a Babel Spire when they want to communicate to the parent race that a location is ready to be assimilated.
Major Story Arcs
The Phalanx on Earth were initially formed by a group of human mutant-haters who voluntarily infected themselves with the transmode virus, taken from the ashes of a renegade Technarch called Warlock. Stephen Lang was recruited from a mental hospital to turn the Phalanx members into living Sentinels due to his experience of making unique sentinels to combat the X-Men many years before. He was to become an interface - not actually infected with the transmode virus himself, he was intended as a buffer to keep the Phalanx on track for their intended purpose. He was assisted by Cameron Hodge, a traitorous former friend of Archangel who had obtained immortality from the demon N'astirh, who did infect himself, and who had been the one to kill Warlock some years before in a prior attempt to infect himself with the virus.
The main task for these members were to assimilate any mutants into their collective. This task was deemed impossible as the mutants who were targeted possessed a resistance to the virus. They decided to organize an attack on the X-Mansion, kidnapping most of the X-Men and replacing them with Phalanx members in disguise in an attempt to use the X-Men's knowledge base on the mutant genome to solve the problem. The impostors were soon discovered from the mutant Banshee who was absent during the kidnapping and with the aid of the contained Sabretooth, Banshee able to rescue Emma Frost and Jubilee from the beings. Banshee, after discovering that the Phalanx had accessed the location of several young mutants for use in further study, then destroyed the knowledge base in an attempt to prevent the Phalanx accessing any further information.
Banshee soon contacted some X-Men who were scattered around the globe such as Wolverine, Cable, Cyclops and Jean Grey. Banshee's group were followed closely by the Phalanx, who impersonated several beings, notably cops. The group was joined by the mutant Synch, who could copy powers which proved helpful as Banshee's screams easily subdued many Phalanx entities. The rest of the targeted mutants were being held in an old, decommissioned battleship. One of the Phalanx disguised itself as an imprisoned mutant, a farm-boy type. This disguise was suspected by some of the prisoners. Eventually, the group saved all the targeted new mutants but one - Blink, who sacrificed herself to save the rest. One of the original Phalanx entities was destroyed in this attempt, parts of his physical body detached from the rest. He was unable to survive the trauma.
Scientist originally infected volunteers with the transmode virus in a bid to create techno-organic versions of the Sentinels. However, the result of these experiments the Phalanx wanted to convert all life on earth into techno-organic beings. Since the Phalanx could not assimilate mutants genetic structure, they instead tried to kill them. The X-Men were able to destroy most of them, but they have since spread into space and are now a threat to the Shi'ar empire.
The Phalanx returned after the events of Annihilation under the control of the rogue A.I. called Ultron. These members are of a new breed of the group which pose as the main villains and threat in what would be known as Annihilation Conquest, taking over the Kree Empire, capitalizing on the devastation caused in the universe by the Annihilation Wave.
The Phalanx succeeded in taking control of the Spaceknights and then their new allies the Kree. When the Kree began the test of their new defensive network, the Phalanx managed to corrupt the system directly through the Kree homeworld of Hala, surrounding the entire Kree Empire in an inescapable energy barrier. The also spread their Transmode Virus, turning all organic life forms into Phalanx, fully under their control and members of their single minded matrix. High powered beings such as Ronan the Accuser were made into their group Select by Ultron, used to cut off any attempts to stop the spread and control of the Phalanx.
The Kree not under control fought back against their oppressors, as well as Quasar (Phyla Vell), Moondragon, Adam Warlock, and Starlord and his Dirty Half Dozen and ultimately obliterated the entire race after Ultron was defeated. Those who had been infected by Ultron's version of the transmode virus were later cured.
Given the powerful nature of the Phalanx, different individuals and governments attempted to experiment with the alien race.
-A British Intelligence group known as BlackAir had aquired several Phalanx specimens, and determined how to control them. They used at least one Phalanx (which had a Brood as its template) as a guardian warliquid at their London headquarters, the Blackwall. They kidnapped and manipulated the demon known as Douglock as part of a plot to gain outright dominion over the Earth by the channeling of demonic energy.
-A similar attempt by the Chinese Government was conducted on a technokinetic mutant boy so that he could control Phalanx members. The government scientists purposefully implanted the young boy with the Techno-Organic Virus to see what would happen and the T-O virus had an interesting reaction with the young boy. Both the boy and the part of the Phalanx became transformed into a new being calling himself Paradigm, who not only had the Phalanx's penchant for shapeshifting but was able to control the minds of people that he covered with his techno-matter. Somehow Paradigm found himself allied with King Bedlam's group of Hellions only with the purpose of discovering himself. After the Hellions were defeated by X-Force, Paradigm has not been seen since.
-After a battle with the Silver Surfer, Cable was partially lobotomized in order to save his life from the angry herald of Galactus. Now trying to save him, Deadpool tracked down the Fixer to save Cable. Deadpool was in possession of a Phalanx fetus, having taken it from an AIM facility, which Fixer surgically grafted onto his body. After a brief scuffle for control, Cable's mind overwhelmed that of the fetal alien and made it subservient to him so that it would not try to "assimilate" him into the collective.
The Phalanx originates from sub-atomic particles, which Jubilee is able to detonate and destroy.