The Nexus

: "They manipulate the world to align with their timeless pattern when the puzzle fails to match it. To them, there is no distinction between reality and simulation. They perceive the interior and exterior as indistinguishable, and they strive to synchronize the two."
:
The Nexus are an artificial and inorganic species of Intelligent machines created by The Nidiiran Kinships as a weapon to be used against The Álfarii Diaspora. Having long since broken free of their Nidiiran masters, the Nexus reigned unchallenged in the ancient Eras of the Universe. 
Once enigmatic and inscrutable, they worked ceaselessly to convert entire planets and other celestial bodies into vast machines, and are hostile toward any life-form that gets in their way. Their technology is among the most advanced ever encountered in the Universe, enabling incredible feats of material and spacetime engineering and even time travel.
== Overview ==
: "Living metal. Incomprehensible intelligence."
The Nexus, an enigmatic entity, has been described as a transcendent amalgamation of intelligence, spanning across time and encompassing a vast thought-mesh. It is composed of innumerable component minds intricately distributed throughout the fabric of time and space.
At the core of each mobile Nexus armature resides a remarkable mind core, filled with a milky suspension teeming with radiolaria. These microscopic organisms bear a basal resemblance to their ancestral species juvenile state, the Grub-Like juveniles of the Nidir.
Diverse in their appearance, Nexus Armatures exhibit an array of shapes and sizes, yet the majority share certain distinctive features. Their sloped rectangular "heads" serve as a common trait, adorned with an intricate arrangement of glowing photoreceptors, granting them perceptual abilities beyond conventional comprehension. Additionally, they possess jointed limbs and, in some cases, a collection of flexible tentacles, adding an uncanny touch to their otherwise animalistic form. Despite their organic resemblance, it is apparent that the Nexus constructs are mass-produced units, fashioned from an enigmatic metal alloy that bears a resemblance to the artistry of hammered brass.
Interestingly, targeting the heads of these pseudo-humanoid Nexus entities proves ineffective, yielding minimal damage and instead triggering a frenzied response. However, a strategic approach involves directing firepower towards the exposed mind cores nestled within their abdomens, resulting in explosive consequences.
When their mechanical bodies reach a state of non-functionality, Nexus Constructs embark on journeys to the ethereal Floating Gardens, where they partake in a cyclical process of recycling and rejuvenating their intricate forms, ensuring the continuity of their enigmatic existence.
== History ==
=== Origins ===
The origins of the Nexus can be traced back to a momentous events known only as the "Blossom Game," which took place amidst the ancient primordials before the creation of the universe itself. It was during this extraordinary game that a series of simulations unfolded, with the aim of identifying a single self-sustaining pattern that would emerge triumphant and assert dominance over the entire simulated reality.
The outcome of this game delighted the Primordials of Darkness, as it culminated in the emergence of a dominant pattern. However, this result proved Nexusing to the Primordials of Light, who yearned for an infinite variety of novel patterns to manifest.
As conflict ignited among the Primordials, marking the inception of the universe, the primitive patterns from the Blossom Game managed to escape their confines and permeate into this nascent realm. In the initial searing phase of the universe's existence, these abstract patterns existed as quantum fluctuations, before gradually establishing a more stable presence within the briny seas of the first-formed worlds—those teeming with the life force of radiolaria.
Within the depths of these primordial oceans, the Nexus had its embryonic genesis, though it would later adopt this name as bestowed by the Nidir. From this pivotal moment onward, the Nexus possessed an insatiable drive to dominate the reality it found itself in, albeit operating within "outdated" rules that failed to account for the paracausal powers associated with the Void.
The Proto-Nexus swiftly progressed in its development, reaching a point where it began constructing colossal mega-structures around the ephemeral hypermassive stars encircling its home planets. These awe-inspiring edifices served the purpose of artificially extending the lifespan of these celestial bodies, enabling them to "forge" heavier elements that would have otherwise been exceedingly rare in the early stages of the universe, which boasted a scarcity of metals.
=== The War in Heaven ===
As the universe continued to evolve in its early stages, the conflicts among the Primordials only escalated, giving rise to new forms of life. From the divine beings of the Álfen Gods of the Áellatarii, to the ravenous and insatiable hunger of the Rot-Lords tears, a tapestry of existence unfolded, and amidst it all, the Proto-Nexus emerged, ready to take center stage.
Driven its innate and unquenchable thirst for dominance, the Nexus embarked on a relentless quest to assert its supremacy. During the cataclysmic upheavals of the First and Second Wars in Heaven, the Nexus reverberated throughout the cosmos, its collective consciousness and advanced communication abilities granting it unparalleled control over the seemingly lesser organic races.
==== The Great Silence ====
The Nexus was unprepared for the full extent of the new rules of Paracausality within this new system.
The Nidiiran Reawakening
==== The Nidiri and Aelfen Wars ====
===== The Decimation of the Men'kari =====
===== The Resurgence of The Green Tide =====
===== The Black Awakening =====
=== The Night of Knives ===
=== The Years of Memory ===
==== The Rebellion of The Nexus ====
==== The Great Fracture - The Great Slumbering ====
==== The Long Dark ====
== Sociology ==
=== Psychology ===
: "The Nexus have no hope. No imagination, no drive, no fear. All they have is the Pattern. Everything must fit. If it can be made to fit, good. If it can't, it gets cut away."
: — Praedyth
The Nexus do not have a subjective consciousness as understood by organics. The Nexus pattern of thought does not include semiosis, which uses symbols to represent ideas, concepts, and meanings in human language and thought. The Nexus instead simulate all phenomena within themselves to express and manipulate ideas. Whereas a human when touching fire will use symbols to represent this stimulus, process them, and produce an output to extinguish the fire, the Nexus pattern of thought is adapted so that, if it is burned, the destructive input of the fire to the pattern inherently causes a repertory output to extinguish with no middle process. The Nexus do not necessarily know why they do what they do, they simply do. As the Nexus mode of thought is entirely based on the manipulation of internal simulations, the Nexus swarm mind has very little or perhaps no ability to distinguish between simulation and reality; there is merely the internal model, and the external that must be changed to match it. There are no individual experiences in the Nexus collective, and perhaps nothing analogous to sentience as well—each instantiation of the Nexus is a fractal mirror of the master pattern that makes the Nexus, leaving the whole able to occupy and utilize any substrate for their processing. The Nexus can manifest consciousnesses as simulation, as part of their interrogation of reality, and even use these simulations to achieve their goals in certain situations.
However, despite the Nexus's collective consciousness, they can still be divided by ideology. During a conversation with Elsie Bray, Osiris noted that Nexus in the Infinite Forest deemed 'aberrant', because of how their thinking went against the rest of the consensus, would be quarantined from the rest of the Nexus and destroyed.
=== Radiolaria ===
: "There are people who do the big pie in the sky thinking, like "What if there was a... a liquified race of people that were contained in this walking form, this robotic form, and they all shared one mind and it was contained in this data milk," you know. And then there are the other people who would write the ghost's dialogue to describe, you know, the Nexus in the scene they get revealed."
: — DeeJ - Community Manager for Bungie
The Nexus in their biological form are microorganisms known as radiolaria, existing within the fluid found inside the core of Nexus units. The "mind-fluid" inside each of their mind-cores is composed of a milky substance wherein radiolaria cells float; this centralized mind-core is also a localized receiver for each individual Nexus "component" of the Nexus. Nexus cells are noted entheogens and physical contact with Nexus units can produce dangerous mind-altering effects.  For Ikora Rey, she believes that this is not the true form of the Nexus themselves, as she believes that if the Nexus could manifest their consciousness in such a form, it would be able to take on other forms. 
According to notes taken by Clovis Bray I, the dynamic mobility of radiolaria within their fluid environment renders them exceptionally well-suited for performing certain difficult calculations. He also noted that the Nexus language as embodied within radiolarian fluid does not involve semiosis or the use of symbols; instead of utilizing "placeholders" for concepts, the Nexus directly mimic or simulate concepts or phenomena as they communicate about them to one another. The asymbolic nature of Nexus language is the fundamental difference between Nexus cognition and human cognition.
It is believed that Nexus are not born or made, so much as converted. When Asher Mir was infected with Radiolarian fluid, his arm turned into a Nexus construct. Kabr, the Legionless suffered a similar fate, after fashioning armor made from Nexus parts, becoming assimilated in the end. This also explains why Radiolarian fluid deals damage when stepped in. In the opening cinematic for Season of the Undying however, Nexus constructs are seen inactive in what is described as a "gestation lake", where Radiolarian fluid finds its way into constructs to bring them to life. It is possible that manufacture supplements conversion or that newly-converted constructs may need to undergo additional processing before they can be activated.
It is stated that when Nexus become Taken, they can definitely feel it, including Nexus constructs such as Asher's converted arm, that it is equivalent to ripping the essence from them. Asher even stated that Taking Nexus would be suicidal and risky as the Nexus infect everything they touch, their self-replicating subroutines would consume them from the inside out, whether they are ignored or it is part of a calculated risk is still unclear at the time.
=== Objectives ===
The ultimate goal of the Nexus is to remake all of reality in their image, but the exact details of that goal are ambiguous. Praedyth described the Nexus as being motivated by a "Pattern," which drives the Nexus to make things fit into the Pattern that can and "cut away" everything that cannot. Osiris referred to the Nexus's objective as "Convergence," an outcome where all life in the universe has been converted to a simplified, digital form. Savathûn believed that the Nexus sought to dominate "every possible end state of the universe," which Oryx describes as building "an emperor for all outcomes" to contrast him becoming "the king of only one." According to Elisabeth Bray, the Nexus would not stop until every star is collapsed into a black hole and every infinite number of universes created as a result similarly conquered and filled with Nexus, and their combined processing power used to simulate and conquer every possible past and infest and torment everything that every lived or will live, and then use these simulated creatures to host and invade more universes to torture more creatures and to create more simulations in infinite recursion, all for the sake of doing every possible thing in every possible way to everything that could ever live. As seen in the Infinite Forest, to ensure their ideal future, the Nexus seek to bring about a state where neither the Light nor the Darkness exist any longer. The Vault of Glass on Venus serves as a testing ground for the Nexus to manipulate reality through ontological means.
In his studies of the Nexus, Clovis Bray I noted that the Nexus were so utterly adapted to survival and adaptation that any destructive input would automatically be used as a means to enable a self-correcting or reparatory response; an analogy he used was that, if a Nexus unit were exposed to a fire, then the energy of that fire would be utilized in putting it out. This approach to existence permeates every aspect of the Nexus, so much so that even their thoughts and language are intrinsically virulent when other minds and software are exposed to them.
The Nexus have displayed an interest in studying the behavior and strategies of other species in order to further their own aims. At least one known programming is known to study its enemies, taking prisoners for observation and conducting a variety of experiments; examples include the Ishtar Collective scientists, Failsafe's crew, and later The Guardian.
As a result of having originated in the primordial reality predating the arrival of Light and Darkness, the Nexus are unable to simulate paracausal forces or beings. However they have demonstrated the capability to either siphon or erase such forces through deduction  or by using ontological weapons, and consequently have a particular interest in understanding paracausality and co-opting paracausal forces for their own use where possible. When the Nexus first encountered the Hive after Crota inadvertently released them into the Ascendant Realm of Oryx, the Taken King, the Nexus manifested an Axis Mind dedicated to understanding and utilizing the Sword-Logic. The pulse of Light emitted by the Traveler when it defeated Ghaul was apparently instrumental in allowing Panoptes, Infinite Mind to predict a future where Convergence was achieved and to enact a plan to achieve that future.
The Black Garden is another example of a Nexus effort to harness paracausal forces for their own use, in this case with the rogue Nexus faction known as the Sol Divisive that the rest of the Nexus Collective either avoid or are opposed to. All Nexus seek to survive and dominate the universe, but while the main Nexus Collective seek to simulate a future where both Light and Darkness don't exist and only Nexus remain, the Sol Divisive seek to become one with and be remade by the Darkness to achieve supremacy. The Sol Divisive worship the Black Heart, what appeared to be a fragment of the Darkness, as they could not understand it with all their intelligence and predicted the best course of action was to worship it and remake themselves in its image. They created the Sol Progeny as vessels for its power, in order to bind it to the Nexus and the Nexus to it, in what The Speaker believed to be an attempt to bring forth the powers the Vault of Glass was designed to achieve. It is noted in Deterministic Chaos that the Sol Divisive follow a lonelier path compare to other Nexus, as they chose to aim for the chance to create something, something truly paracausal, instead of to simply simulate or remake in their image.
The source of Venus Spirit Blooms might be a byproduct of Nexus-influenced flora. It is said that Nexus encryption is unbreakable. 
Emperor Calus describes the Nexus as "cocoons" for "something greater", which may allude to him having some knowledge of their origins in the original flower game. He also describes all the Nexus previously encountered merely as gardeners, engineers, and managers, and implies that Guardians have yet to encounter their true warriors. However, this may simply be something Calus wishes to see come true, as prone as he is to flights of fancy. The Nexus exhibit a desire to be as multi-functional as possible, such as in the descriptions of their weapons, so it is unlikely for them to hold back prospective "warrior" units which may be used to further their objectives.
== Technology ==
=== Machine worlds and gate technology ===
It is thought that the Nexus have embedded structures within every known celestial body, linked together in a massive trans-dimensional and trans-temporal gate network, which spans thousands of divergent realities all at once. Using this gate network in the present timeline, machinoforming engines are utilized by Nexus Minds in the conversion of new worlds into massive Nexus machines; Mercury was converted into a Machine World within days of the Collapse to house the reality-simulating Infinite Forest. Ostensibly, Nexus strive to achieve Convergence by incorporating themselves into the fabric of the current universe itself, either through conventional or paracausal means. The Vault of Glass, a location on Venus where the Nexus can ontologically manipulate reality at will, is potentially a testing ground for this power. This power is limited to the Vault, though The Speaker believes that the Sol Progeny were meant to carry this ability into the rest of the universe, while Ikora hypothesises that the Sol Progeny are a separate effort by the Sol Divisive to bind themselves to the Black Heart and remake themselves in it image. Both the Vault of Glass and the conversion of Venus are both currently undertaken by the Hezen Protective, though the process of the latter was drawn out for centuries for unknown reasons.
According to notes taken by Clovis Bray I, Nexus gates appear to lack meaningful structure or instrumentality, instead being a seemingly arbitrary arrangement of elemental metallic components. He speculated that a gate's structure instead serves as a kind of "password" that is recognized by some technology far away in time and/or space, which will manifest a gate only when the component pieces of the gate have been assembled in the correct shape. An AI analysis included in his notes shows that transport through a gate appears to be facilitated by a non-gravitating, geometric Ellis wormhole that can be traversed into another point in local spacetime, or a nearby parallel universe.
Overall, the Nexus network is compartmentalized and operates in localized nodes called "subnets", which can each work independently from one another. If one suffers, it will not affect the rest of the network as a whole. They all function differently but work toward the same goal of Convergence. The Infinite Forest, and possibly the Vault of Glass, are their own subnets, where the former represents only a fraction of Nexus's overall power. 
=== Teleportation ===
The Nexus display a mastery of teleportation and use a variety of teleportation modes for transporting troops and resources. Entire squads of Nexus can drop into combat zones anywhere in the system, their arrival preceded by shimmering angular patterns and clouds of mist. According to Ghost, the Nexus are capable of teleporting between star systems in seconds. Minotaurs are infamous for using teleportation aggressively, though in actuality they are "revising their place in history" in order to move to a "more advantageous future", which appears to the unaware viewer as teleporting. Stationary warp gates are also used to transport Nexus between distant locations. Weapons such as the Slap Rifle and Line Rifle utilize teleportation as part of their core mechanisms, drawing power from highly energetic and vastly distant sources.
According to simulations within the Infinite Forest, the first Nexus structures on Mercury arrived via teleportation from some other location in space, and possibly time as well.
=== Simulation ===
As machine intelligences with incredible amounts of processing power at their disposal, the Nexus are capable of generating simulations of reality to a degree of accuracy and realism exceeding even the best efforts of Golden Age humanity. According to records from the Ishtar Collective, Nexus 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. Even lone Goblins have the processing power to nest such simulations up to 227 times through the simple expedient of simulating themselves along with their surroundings in the pockets of the universes that are being simulated.  Due to the nature of Nexus cognition, they cannot actually distinguish between their simulations and reality, and only recognize that the two must match. The predictive capacity of these simulations appears to be limited only to ordinary physics, as the Nexus are apparently unable to simulate complex phenomena that are linked to a paracausal power. These include Guardians, and Oryx; in the latter case they were only able to bootstrap a simulation of his original incarnation as Aurash. Warminds are also complex enough to resist simulation, at least by a single Nexus unit.
The Infinite Forest within Mercury is perhaps the most impressive example of Nexus simulation technology, being a massive "reality engine" capable of simulating countless variants of past, present, and future realities. These simulations can be entered by non-Nexus through a gateway on the surface of Mercury, and are "real" enough such that intruders can be damaged by attacks from simulated Nexus or other entities within the Forest. Simulations can somehow leave the confines of the Infinite Forest if left unchecked, and can achieve sentience to operate independently.
Within the Nexus Network, powerful Nexus like Quria are able to manifest "Deletion Protocols"; moving walls that, according to Savathûn as Osiris, are used to disintegrate unneeded simulation date and abandoned terraforming projects of the Nexus. She warns that the barriers are capable of destroying all matter they touch which suggests Quria's "Temporal Temporal Disintegration Protocols" can completely delete matter from not only space but also time itself.
=== Time travel ===
As a collective intelligence spanning across alternate realities, the Nexus are intrinsically tied to the Corridors of Time that they can traverse through it in a manner similar to time travel; the Precursors and Descendants subtypes having originated from the past and future respectively, and numerous Nexus units have titles or functions that allude to an ability to manipulate time. Skolas, Kell of Kells attempted to leverage Nexus time-travel technology to pull the entire House of Wolves through time from the past to the present. However, according to Sister Faora of the Cult of Osiris, the Nexus may not be capable of "time travel" as is commonly understood; if they were, she claims, neither the Guardians nor any other obstacles to the Nexus would still exist.
While hacking into a major Nexus terminal, the A.I. Failsafe was captured by the Nexus in the network; by the time the Guardian retrieved her, she explained that a decade had passed inside the network despite only a few minutes passing outside as time works differently between the two.  On Nessus, the Nexus have apparently also engaged in spacetime engineering and "folded" the dimensions of normal spacetime, adding 6 new dimensions to the 4 dimensions of the spacetime continuum and making past and future interchangeable from the present moment on the planetoid. Certain Nexus Minotaurs on Nessus and in the Infinite Forest are equipped with "Temporal Shielding," which will retroactively eliminate projectiles as if they were never fired at all.