Covenant (Earth-2124)

The Covenant was a religious hegemony consisting of multiple extraterrestrial species that controlled a large portion of the Orion Arm and beyond in the Milky Way galaxy. It was originally a mutual alliance between the san'shyuum and the sangheili following the signature of the Writ of Union, only to expand and include six other client species, united in the worship of the orokin as gods and the Halo Array as tools of transcendence. After making contact with humanity, the Covenant waged a genocidal war against them following an intricate plot by the Hierarchs to hide a discovered connection with the orokin. This eventually led to internal conflicts, that, coped with the human resistance, the discovery of two Halo rings and the emergence of the xenomorphs, led to the Covenant's downfall and ultimate dissolution.

Technology
Covenant technology is noted by humans to be more imitative than inoperative, with most of them being either a mimicry or reverse engineering of salvaged orokin artifacts and items they found through their expansion, including their perfect slipspace navigation, instantaneous interstellar communication, manipulation of plasma and gravity, as well as repulsor-based technology. Many of their achievements were based upon the digging of material in shield worlds found by the Covenant in the first centuries of its existence.

Despite its lack of innovation, the Covenant is incredibly apt at advancing the bridging gap in technology between the species it inducted into its rank. During the First Battle of Shanxi, the Covenant was able to learn the functionality of human computer systems and English after hacking computer storage from destroyed ships, which was pivotal into the Covenant's understanding of the workings of human military operations, business, and technology, leading to the creation of the Cole Protocol. During the Fall of Reach, the Covenant covertly dismantled Reach's telecommunication network in order to prevent the planet from calling reinforcements, as well as the placement of dozens of spires to deploy massive forces without being detected.

Duo to the Covenant culture's religious taboos, they were prevented from fully reaching their full potential at exploring the intricacies of orokin technology, something only the Hierarchs were considered holy enough to manipulate. This leads the Covenant to only imitate the underlying effects of the orokin technology they reverse-engineer, while the hidden science remained unknown and impossible to understand, with a prime example being the hegemony's usage of plasma instead of hard light, which remained a complete mystery to the faction. The Covenant also never utilized AI and androids because of their religious doctrine, as they believed a powerful machine betrayed the orokin to the flood during their ancient conflict, and that they should not be underestimated. The few AIs utilized by the Covenant were unintelligent, and used for minimum work, such as Sorrow, who served aboard the Ascendant Justice.

Despite their lack of knowledge over hard light, they were able to achieve some of it, such as the omni-tool of the Prelates, but it made up for their vast understanding and utilization of holograms, advanced enough to reproduce realistic and tangible simulacra of physical objects, including individuals, such as was the case of the holo-drones, which reproduce independent copies of its user that is capable of inflicting actual physical harm to enemies. They also used force-field technology in numerous capacities, such as to power the thrones of san'shyuum to contain beverages to the colossal energy barriers that protected High Charity.

Covenant architecture was curved, techno-organic, and sophisticated in style, based on designs of san'shyuum of old, as well as loosely sangheili architecture in design. Despite the san'shyuum's obvious influence in vehicles, many adopted sangheili aesthetics, primarly based on animals that inhabits Sanghelios and other sangheili colonies. Their architecture was mostly purple, although shades of blue and white could also be found, shared mutually by their buildings, weapons, vehicles, and weapons, with material unknown to the UNSC.

Medically, the Covenant was very advanced, with surgeries and treatments that extended the life of the san'shyuum, who live up to their 300s. Prelates also used biological augmentation and enhancements to fortify their frail bodies. Every battleship had special surgery suites which treated injuries and magnetic splints, which hold broken bones. Huragok also provided medical support during combat situations, alongside their primary engineering function.

Spacecraft
Interstellar travel was made easy to the Covenant species because of the hegemony's ability to reverse-engineer advanced technology they found. Ships that entered slipspace, much like those of humans, travel faster-than-light, but unlike humanity's slipspace drive, those employed by the Covenant were more efficient and powerful, able to perform accurate jumps to designated locations without suffering temporal fluidity. However, upon the jump's conclusion, Covenant ships experienced temporary power outages, making them vulnerable to enemy attacks.

Covenant ships used repulsor engines for propulsion in space, which were propelled through the mixture of gravity waves and reactive plasma displacements, although the factual means to do so remain unknown to human understanding. Many of the Covenant's ships and vehicles were equipped with anti-gravity technology, enabling them to hover an atmosphere and perform frictionless movement of vehicles through the ground. Many of the hegemony's manufacturing plants, such as the Assembly Forges, used sophisticated methods to allow freedom in a ship's design, allowing each commander to personalize their ships despite the uniform design they all sported.

Weaponry
Majority of the Covenant's weapons consisted of plasma-based directed-energy weaponry, but many designs also featured pulse lasers, particle beam weapons, antimatter explosives and crystal-based weponry, defying the known laws of mechanics to human scientists, as their weapons feature neither radiative, electrical, or physical contact between the firing mechanism and the weapon's trigger. The plasma weaponry use rechargeable power cells, which provide power to the weapons' internal components, being effective, but crude in design and capability, with most of them overheating. However, most of the weapons possesses vents that allow them to open and discharge the excess of heat and plasma, and once the energy is depleted, it must be either recharged or discarded, meaning that the workings of a plasma weapon recharge remains unknown to the UNSC. The plasma pistol and the plasma rifle are the most well known plasma weapons, while plasma cannons, plasma torpedo and plasma mortars are the most commonly fielded in vehicles and strategic positions.

The Covenant utilized projectile weaponry, although to a lesser degree, with the most known of them being the needler and the needle rifle, using chemicals that form hard, razor-sharp crystals known as blamite, found on Suban, one of Sanghelios' moons. These crystals are fired at high speed, which allow the attacker to strike its target with deadly precision at long range. Needlers penetrate both flesh and armor, quickly exploding into thousands of sharp and tiny fragments that either maim or cripple its target. However, once a certain number of needles have struck the target, they detonated, killing the target instantly in an explosion.

After the jiralhanae's induction in the Covenant, their native weapons started being utilized, although mostly by themselves, with feature spike-like metal projectiles instead of plasma and crystals, akin to human bullets. They also used conventional explosives, incendiary grenades, sharp blades and hammers. Their weapons range from the Spiker, to the Mauler, and the Brute Shot.

In addition to their conventional weapons, the Covenant also utilized melee weaponry, which included the widely known energy sword, used exclusively by the sangheili, which is a ceremonial and ancestral tool used in their cultures for ages. The other is the gravity hammer, used exclusively by the jiralhanae, and much like how the energy sword is cultural to the sangheili, so is the gravity hammer to the jiralhanae, which generates a gravitational field that can maim a target to pieces in both close and long quarters.

Vehicles
Covenant vehicles used advanced anti-gravity technology for propulsion, being armed with directed-energy weapons of varying strength. Despite being faster compared to UNSC vehicles, the Covenant vehicles were far more unstable duo to the uneven terrains it needed to operate in, as all Covenant vehicles, except for those of jiralhanae origin, are made of much more advanced alloys than that of humans. The UNSC nicknamed all of the hegemony's vehicles based on supernatural entities in human history, such as ghosts, wraiths, spirits, seraphs, and banshees, among many others. Despite being more primitive, jiralhanae weapons were successfully incorporated into the Covenant, showcasing the design aesthetics valued by the jiralhanae (strength, brutality, and practicality), as opposed to that of the sangheili (strength, tenderness, and elegance). Unlike the other Covenant vehicles, jiralhanae vehicles are not named after supernatural entities, but to acts of brutality, such as chopping and prowling.

Sphere of influence
The Covenant's interstellar empire was mostly based in the Orion Arm of the Milky Way galaxy, although they possessed outside domains, with its capital being the mobile High Charity. The Covenant encompassed thousands of star systems during its height, with a complex governance and set of politics; its size was so massive that planets and entire systems would disappear from the records at High Charity, only for contact to be re-established decades, or centuries later. The Covenant High Council was the responsible for organizing and administrating the hegemony's territories, including the allocation of resources to its thousands of worlds. Because san'shyuum were the ones to administer star systems, many were left in chaos and disarray after the disappearance of the few living san'shyuum who weren't killed by the xenomorph once it invaded High Charity.

The kig-yar, yanme'e, and lekgolo already had planetary colonies before being discovered and forced into the Covenant, which later became absorbed as part of the hegemony. As it expanded through the Orion Arm, the Covenant acquired more and more territory, with colonists being deployed both on planets and orokin installations such as shield worlds. However, despite its enormous size and expansion, the Covenant left planets alone unless it held any religious value. Sangheili colonies, many of which were established before the formation of the Covenant, were deemed the most important worlds in the hegemony. After the incorporation of the unggoy and the jiralhanae on the Covenant, many started to live on resource-rich planets alongside the other species to guard them, although both species lacked the individual power to mine resources themselves.

Following the fall of the Covenant, and both the near extinction and disappearance of san'shyuum, most Covenant colonies fell in control of the multiple splinter factions, although others were taken by individuals without any affiliation, such as sangheili civilians and kig-yar pirates. Other planets became embroiled into civil war between various individuals and factions who wanted to take them to themselves. Joint Occupation Zones were established between the Swords of Sanghelios and the UEG in order to improve the tense post-war situation between sangheili and humans.

Trivia

 * Orion Arm art made by The Chronothaur.