Rhiln

The Rhiln (known to the Covenant as the Anathematics) are a species of hexatuple-limbed congruents believed to be native to the planet of Dryy'sh, located in the outlying regions of what is now the Holy Ecumene's High Coreward Expanse. In recent history, the Rhiln served a place in the Covenant empire as one of the many fringe species, though in the past held a large series of interstellar holdings, numbering around 110 systems. In this era, the Rhiln had advanced research into artificial intelligence and related fields and willingly joined their species together under one compound intelligence. By the time of first contact with the Covenant in 149BCE, the Rhiln were in the process of finalising the construction of a large dyson swarm surrounding their home star. Ultimately, the Covenant declared holy war upon the Rhiln and began a conquest of the Rhiln territories, leading to the shattering of the dyson swarm and the near-extinction of the Rhiln, with the survivors incorporated into the Covenant as part of the Covenant fringe.

History
The Rhiln maintained comprehensive records of their history, which they openly shared with the Covenant during initial contact in the hope that this would lead to a better understanding between their two cultures. Instead, it only convinced the Covenant of the magnitude of what was to them an unforgivable sin. However, it does mean that the history of the Rhiln is exceptionally well-documented for an obscure fringe species.

Rise of civilization
The Rhiln evolved on Dryy'sh as hexatuple herbivores with a strong herd mentality. To offset their natural predators, the Rhiln quickly learnt the benefits of tool usage and had a fairly rapid rise from hunter-gatherer societies to industrialism. The Rhiln quickly spread out into their home system, but were quickly stymied by massive physical disadvantage outside of the low gravity, flat plains of their homeworld. As such, the Rhiln invested heavily into biological augmentation and cybernetics to compensate for these deficiencies, beginning a slow but gradual transition into a heavily "transrhilnist" (cf. transhumanist) society in which nearly all individuals expressed a certain level of alteration of some form. This transition was not sudden, with biological "naturals" and augmented post-rhiln existing alongside one another for centuries. By around 2000 years into this process, nearly all Rhiln had made the transfer into digital beings, and formed a vast interstellar empire covering around ninety-five systems.

The Rhilns' strong herd culture proved beneficiary for the species in their evolution, as the natural instinct for cooperation for mutual benefit allowed the Rhiln to offset many of the dangers of climate change, war and industrialism that plagued other species such as the Unggoy, Jiralhanae or the now-extinct civilisation of Netherop. The desire for such a close-knit community saw the Rhiln value oral traditions passed down from elders to adolescent, with shaman-like figures recording the histories of a given clan in minute detail. As such, when research into augmentation technologies saw the potential for Rhiln communities to share and exchange memories, this was eagerly adopted by many of the Rhiln. Each clan developed in essence, a collective shared memory bank that could be shared by any individuals within the clan - allowing a grandfather to pass down his memories and experiences onto his sons and their sons. For many, adding to the shared memory pool and becoming one with the tribe was a major part of the transition from adolescence into adulthood.

As this technology became more widespread over the centuries, it evolved from merely sharing memories to real-time memory sharing. It was not uncommon for smaller familial pairs to have some sort of real-time sharing of thoughts and memories, effectively allowing two or more individuals within a given network to instinctively know the thoughts and feelings of those surrounding them in the same way they may recognise the temperature of their hand. From here, the road to a species-wide compound mind was well-set, and within the relative blink of an eye, nearly all Rhiln individuals had joined the wider shared consciousness of the Rhiln and the line between individual Rhiln and the wider Rhiln species blurred.

The unification process was not without its hindrances; at least two major conflicts were fought in the Rhiln home system as rival compound entities fought to secure their own dominance - or independence from - the overmind. The rise of this technology paralleled a similar evolution in the development of artificial intelligence with Rhiln smart AI equivalents exhibiting extraordinary power, and the final of the unification wars fought by the Rhiln had very little conflict in the physical world - instead a war fought in the metaphysical realm by collective consciousness' and AI (themselves also linked into their respective creators' overminds). For the majority, the war was not fought over the choice to join the collective shared mind - nearly all Rhiln had long-since joined one of the several predominant collective minds by this era - but over which of the collective minds may form a "base" consciousness around which the others' memories and intelligence may be added to. Despite this, a faction of Rhiln completely disinterested in this shared collective did emerge. In general, the fairly peaceful nature of the Rhiln saw these "Naturals" and the Rhiln compound mind exist with relative harmony - for the Rhiln collective, there was very little desire to forcibly subsume others into the consciousness partially due to the fact that any memories of hostility or fear from the unwilling would be shared across all Rhiln.

Although the Rhiln collective and the natural Rhiln existed alongside one another with relatively little conflict, this was not an agreement of mutual compassion but rather choosing to ignore the other. As such, the Rhiln collective continued its advances into technological enlightenment and interstellar travel, proceeding to construct vast generation ships to colonise the outermost reaches of the home system, and then larger craft to journey through the interstellar void, unhindered by the need to preserve individual Rhiln as long as the compound intelligence survived - individual sub-consciousness' may survive in the collective metaphysical ether, unbound by the limits of the physical bodies they had evolved in.

This contrast between the Rhiln collective and the naturals reached its peak when the Rhiln collective intelligence ultimately determined the decision to begin the construction of a dyson swarm surrounding the species' home star. The Rhiln had long-since become a Type-1 civilisation, and determined that their only logical way to further advance their own evolution would be to begin truly harnessing the output of their home star. At this point, the Rhiln collective entities had long-since abandoned all need to care about the physical world, and the bodies of the Rhiln were viewed simply as ways to interface with the physical realm - Rhiln entities within the compound intelligence outnumbered physical Rhiln bodies by several orders of magnitude, and the requirements to power the physical hardware of the Rhiln were becoming unsustainable. This lack of interest in physicality also saw a decline in the interest of the Rhiln in preserving natural life on their homeworld - simple fauna and flora were to the Rhiln intelligence what single-celled organisms were to the natural life, and the Rhiln viewed themselves as having entered the next stage of evolution. The encasing of their star dimmed the output of light shining on their homeworld significantly, beginning a slow process of environmental collapse - something that was largely ignored by the larger Rhiln collective. If the Rhiln were to construct their mega-project, their homeworld would provide the very resources and minerals needed for such a construction anyway.

Nonetheless, this presented an issue - that of the Naturals. Many of the Rhiln collective felt that they should be abandoned like the other life on their homeworld, though many more argued that the Naturals were still Rhiln - they may be long-lost brothers, but they were still family. The collective ultimately settled to rehouse the Naturals in specifically-constructed habitats orbiting the star and offered all the chance to join the associated intelligence, though by this point the two had diverged considerably, and many of the naturals had reverted to a pre-technological state. These populations were housed on a series of ring-stations in the dyson swarm and gradually, the homeworld began the process of deconstruction.

Numerous other problems presented themselves to the Rhiln as the construction process continued; although the Rhiln had bypassed the majority of their need for caring about the physical universe they nonetheless faced the issue of the light-speed barrier and its hard limit on the ability of information transfer. To colonise new star systems, the Rhiln collective had been forced to split off constituents to oversee this star systems, with sporadic transmissions keeping the consciousness' in touch once every few years. As the slower-than-light travel of the Rhiln had proceeded further from the home system, the light lag had become too big of a hurdle to counter and expansion effectively stopped for millennia. This issue was further faced during the construction of the dyson swarm, as even sending signals to the other side of the swarm presented a notable light lag problem that needed to be solved. As such, the Rhiln soon developed the capability for slipspace faster-than-light communications to better facilitate information processing among the collective entities. This process soon expanded out into the Rhiln's interstellar holdings and a few brief interstellar conflicts were fought against some errant constituents who had veered off the pre-planned path of the Rhiln.

War with the Covenant
During the Covenant's expansions toward the core-side regions of the Orion Arm in the 8th Age of Discovery 149 CE, Sangheili astronomers identified the telltale signs of dyson construction in the Rhiln home system, and the Covenant prepared a fleet to investigate this potential new signatory for the Covenant. En route, the Covenant encountered one of the Rhiln outlying interstellar colonies, who welcomed the exploratory fleet with open arms. The Rhiln collective intelligence in the system was quickly able to decode the language of the transmissions sent to them by the Covenant fleet and learn the language fluently, opening communications with an offer to "share in the collective memory of the Rhiln and join the harmony". For the Covenant commanders, this statement proved a horrifying corruption of biological life - an affront to the Covenant religion and its tenets against the unregulated adoption of artificial intelligences (itself based on the stories of Mendicant Bias' betrayal during the Diluvial War). The Covenant expedition were quick to begin glassing operations on the planet, and a war of extermination began in earnest - declared the 13th Age of Conflict.

The Covenant were initially successful in the war - the relative lack of experience in warfare among the Rhiln collective saw the Rhiln unable to compete with their more experienced Sangheili counterparts, and the Rhiln continued to offer the Covenant a peaceful resolution even in the face of the Covenant's declarations of extermination, and many Rhiln worlds wilfully offered no resistance to the Covenant conquest. However, these efforts were eventually realised to be wholly futile and the Rhiln collective turned the might of its empire into its defence; while the Rhiln were not as numerous or spread in space as their foe they held an undeniable advantage in technology and sheer processing power. The ability of the Rhiln to run gargantuan simulations allowed the compound entity to effectively teach itself viable space war doctrine and by the tenth year of the war, the Covenant conquest had not only been ground to a halt, but Rhiln warships had begun to make pushes against into the Covenant's own territory. The primary advantage enjoyed by the Rhiln was their collective intelligence and advanced FTL communications - a task force of warships spread out over several light-minutes could nonetheless act with complete and instantaneous coordination unbound by the limits of organic bodies, and as such were able to push their ships to the physical limits of the materials used to construct them, able to outmaneuver their opponents by a severe degree.

For the next seven years, the Rhiln began the process of taking back their lost worlds and the collective began a period of mourning for the intelligences lost in the glassing of the 35 lost worlds. As Rhiln battlegroups cut off the Covenant expeditionary forces from their empire, the now-stranded commanders agreed to make a final push into the heart of Rhiln space - although the Rhiln posessed superluminal communications technology far in excess of their Covenant equivalents, they were still bound by the limits of some delay and as such relied on the in-construction dyson swarm for central coordination and processing. In 156CE, a Covenant force of 122 warships entered the Rhiln home system's Kuiper Belt with a single goal - the shattering of the dyson swarm. The commanders on the Covenant side devised a plan to secure victory for the empire by using asteroids fitted with the advanced energy shielding technology prevalent on Covenant ships, launched on a trajectory directly at the dyson swarm itself. As the asteroids neared the sun, charges scuttled the rocks into millions of pieces of gravel spreading over thousands of kilometres, beginning a massive bombardment which began to pierce the many world-stations of the Rhiln collective. Over the ensuing days, the debris from the destroyed stations began an unstoppable kessler effect even as dozens more rocks continued to bombard the swarm, resulting in the gradual destruction of the Rhiln's grand creation.

With the destruction of the Rhiln dyson swarm, the collective intelligence began to lose its effectiveness in managing the war. Without its central command nexus to direct strategy, the Rhiln quickly lost their operational efficiency and the individual nodes of the Rhiln interstellar network became separated. The Covenant were soon able to reverse their fortunes in the war, and the extermination of the remaining Rhiln worlds proceeded almost entirely unopposed.

During the disintegration of the Rhiln dyson swarm, those habitats which housed natural populations were noticed by the Covenant. Unlike the larger compound mind, these populations were determined to have been uncorrupted by the perversions of the machines and thus the Covenant viewed them as potential new adherents to the Covenant cause. Due to this, the Covenant fleet began aid missions to those habitats, hoping to rescue the populations for relocation elsewhere. Even as this process began, it was noted that the Rhiln collective largely did little to try and save these habitats, and of the roughly 133 recorded Natural habitats only a few dozen or so were successfully evacuated. For their part, the machine-minds did not seem to hold their biological cousins in contempt, but nor did they particularly care about them. For the Naturals, they had long since reverted back to a stone-age civilisation with an advanced knowledge of mathematics and astronomy, but a near-total ignorance of physical sciences and engineering. It is unknown how much of this process was forcibly rendered, as the habitats housing the Naturals were found to only contain the bare essentials of survival - clay, hides, reeds and wood.

The Naturals themselves had some understanding of their place in the universe, and their oral histories told that they understood the machine-minds to be long-lost brothers who had since been reclaimed by the stars. For some of these cultures, they recorded that particularly exceptional individuals in the ways of tradition, history or maths may be reclaimed by the machine-minds but in the examples of the 34 stations rescued by the Covenant, no such reclamation event had occurred within living memory of any individual.

Legacy
The Rhiln left a complex legacy in the cultural history of the Covenant. The war was the first time in which the Covenant had ever found a peer civilisation be it in territorial reach or technology - and the first time the empire had ever had to consider the possibility it may be the victim of external conquest. As such, many of the stories told of the Rhiln to the Covenant populace spoke of an invasive associated intelligence swarm with only the goal of invading Covenant worlds and stealing their populations for integration into the collective. Whether such an act was ever a goal of the Rhiln is unknown. The war ultimately saw a massive level of destruction for the Covenant, with the Rhiln having penetrated fairly far into Covenant space and destroyed numerous fleets in the process. As such, the empire was left in a weakened state for decades, seeing only an increased level of hostility to the idea of artificial intelligence within the Covenant grow, and a further development of anti-automation doctrines. Equally, this opened up new opportunities within the Covenant with a sudden lack of manpower, leading to an increased interest in the idea of incorporating the remaining surviving Rhiln populations.

The genocide of the Rhiln was an action viewed by most within the empire as one of uncomfortable necessity; mere blasphemy such as the Lekgolo's destruction of Forerunner artifacts could be forgiven in time - but the Rhiln collective represented more than a mere blasphemy. For the Covenant, the Rhiln represented a complete perversion of the basic idea of life and individuality, instead embracing the horrors of AI and (for some) even representing the same basic concepts as those of the Flood. While the Covenant viewed genocide as a horrific act, the war against the Rhiln represented a moral necessity. Nonetheless, the regard for the sanctity of life as one of the key tenets of Covenant religious discussion saw the Covenant make extensive efforts in the post-war era to try and incorporate the surviving Rhiln populations into the empire as adherents of the doctrine of the Forerunners. Ultimately, these efforts proved largely fruitless, and the Rhiln survivors were ultimately deemed unable or unwilling to comprehend the ideas of salvation and the Great Journey or the worship of the Forerunners - with the Rhiln eventually incorporated as a part of the "fringe" entities of the Covenant.

These factors combined saw the Covenant renew an interest in incorporating the Unggoy, a species known to the Covenant and gradually incorporated into the hegemony on an unofficial level but ultimately dismissed as too primitive to truly comprehend the ideals of the Journey. Coupled with past experiences with already-existing Unggoy converts, the years after the Rhiln conflict saw a major shift away from this attitude, ultimately culminating in the incorporation of the Unggoy into the Covenant in 214CE. With the Covenant busy assimilating the much more pliable and physically robust Unggoy, the Rhiln survivors were largely forgotten about.

As the Covenant continued to expand, the extermination of the Rhiln remained a black mark on the Covenant's history - and a moment of sorrow of which should never be repeated. As such, the declaration of war against humanity in 2525CE was viewed as a landmark moment, and the second time the Covenant had ever elected to engage in a major war of extermination against a (roughly) peer opponent. As such, the precedent set by the attempted incorporation of the Rhiln at the war's conclusion set similar expectations in the minds of the Covenant leadership, and the ever-decreasing likelihood of such attempts as the war drew towards its climax contributed greatly to the tensions which ultimately set in motion the civil war which saw the empire's collapse.

Despite (and in part because) of these moral quandaries, the Covenant leadership instituted great celebrations calling the entire Holy Ecumene to come together in celebration of the Covenant's victory over the "abominable intelligences". Rather than following the 13th Age of Conflict with an Age of Doubt, as was common when it came to large-scale conflicts, the Hierarchs instead announced a new Age of Discovery to galvanize the populace's belief in the Covenant's holy mission. Song of Victory, a Covenant colony world and later anointed industrial center, was named in honor of the recent victory in the crusade against the Rhiln in the following 9th Age of Discovery.

Today, the remaining Rhiln are an obscure fringe race with a small population. They continue to lead a pre-spaceflight existence on Tyshaan, the world allotted to them by the Covenant, with a small listening station monitoring the species' status. By the 23rd Age of Doubt, the most advanced societies among them had undergone an agricultural revolution and progressed to a bronze-age technology level, likely thanks to the Covenant's influence combined with Tyshaan's accessible natural resources contrasted with the artificial habitats the Rhiln machine collective had housed them in. Over the course of Covenant history, groups of missionaries would periodically make landfall on Tyshaan in an effort to convert the Rhiln population, but the results of these missions were inconclusive and no Covenant-wide Age of Conversion was ever declared. However, several individual Rhiln are known to have converted to the Covenant religion and even been part of Covenant society outside Tyshaan. The Covenant's interference has also shaped Rhiln culture and religion in unintended ways; as of most recent knowledge, a relatively prominent cargo cult has formed among some of the Rhiln worshiping the Covenant as gods. This is one of several competing worldviews among the Rhiln, however, as another major group has the opposite view on the Covenant.

Biology and culture
Rhiln are lithe, six-limbed, bilaterally symmetrical herbivores with a dexterous pair of forelimbs specialized for obtaining food and later technology use. The Rhiln's evolutionary relatives shared the species' hexatuple body plan, but their specialized forelimbs and hands, which evolved from a frontal pair of legs, are an adaptation specific to the Rhiln's genus. They have a head with attentive, side-facing eyes, pronounced ears, and a glossy coat of short fur that exhibits various color patterns. Their heads have prominent crests that play a defensive and ritual role, with the exact shape, size and coloration of the crest varying by sex and ethnicity. Rhiln respiratory systems fully are separate from their digestive tracts, with the species' air-intake and olfactory organs being located on the sides of their necks; these organs are also used to produce sound such as speech, whereas the mouth is solely used for food consumption. Like many species, Rhiln communicate vocally and are capable of producing a range of sounds, from high-pitched chirps to loud howls and shrieks originally used to alert the entire herd of danger or in courtship displays. Even their normal speech is relatively loud by other species' standards; intimate or private conversations are rare. The Rhiln evolved in temperate steppes and woodland environments, and climbing steep inclines or stairs does not come naturally to them; they also have an inborn fear of heights. This, coupled with their multi-limbed anatomy and relatively low resistance to g-forces, made it initially difficult to them to adapt to space travel. In their natural state, the average Rhiln lifespan is about 50 years.

The Rhiln are the only known sapient species to retain an exclusively herbivorous diet as primary food source over their evolution into higher intelligence; normally, the prodigious energy needs of a sapient brain favor the use of more nutritionally dense omnivorous or carnivorous diets. However, the Rhiln have evolved to use the energy from plant matter very effectively, aided by the existence of several high-energy fruits native to Dryy'sh. The Rhiln still need to be feeding more often than average, and in their natural state they spend much of their days foraging for food. This led to a culture that places considerable emphasis on eating and meals, which like many other Rhiln activities is done communally. As a prey species, the Rhiln had several natural predators. Several of these were hunted down to near-extinction after the Rhiln surpassed their predators in intelligence, numbers and technology, though some specimens would survive in nature preserves or zoos.

Although the Rhiln machine collectives had transcended their biological roots, they did not become cold and calculating machines. They retained many aspects of their origins, such as their culture and the appreciation for art, aesthetics and architecture, though these existed within the digital realms to an increasing degree. While their link to the physical world was growing ever more tenuous, the machine-Rhiln had not yet completely abandoned material existence. Though most of the Rhiln spent their time in simulated spaces within enormous server farms, they would also use robotic and semi-biological hybrid bodies to interface with the physical world. These platforms were used largely for utilitarian purposes; individual Rhiln would frequently use them to perform various physical tasks or for novelty reasons such as to gather new and different experiences, but most had little attachment to any particular body. These interface bodies ranged from "rhilnoid" constructs mimicking the species' biological forms to utility drones and large starships, which could house thousands of digital crew. The physical-digital divide also had variety between subgroups of the Rhiln overmind; some colonies were more inclined to activities in the physical world, while others (such as the "main" Rhiln collective in their home system) cared less for the material universe or behaviors akin to their corporeal ancestors. With some noted exceptions, these different philosophies coexisted peacefully among the collective.

During the war, the Rhiln were quickly forced to devise new, more potent platforms for combat uses to counter Covenant ground troops, though much of the war was fought in space. The Covenant quickly found standard infantry boarding tactics effectively useless on Rhiln ships, which lacked conventional decks and were instead interlaced with labyrinthine maintenance pathways meant for utility drones, most of them too small for Sangheili or Lekgolo forms to fight in. In vain, some Rhiln colonies seeking peace with the invaders attempted to create bionic construct-bodies designed to be Sangheili-like so as to appear in a form more comfortable to their enemies, but the Covenant only saw this as further sacrilege and mockery.