Sangheili (Earth-5875)

"On the blood of our fathers, on the blood of our sons, we swore to uphold the Covenant!"

- - Rtas 'Vadumee

The sangheili (Latin Macto cognatus, meaning "I glorify my kin"), known to humans as Elites, are a sapient species of fierce, strong and warrior-like saurians from Sanghelios, who once formed the leadership and the backbone of the Covenant alongside the san'shyuum, united on their faith and reverence of forerunners as gods and the Halo Array as tools of salvation. They have a strong hatred for the former fellow Covenant race jiralhanae, who betrayed them during the Great Schism. During the closing months of the First Contact War, the Prophet of Truth ordered the genocide of the sangheili, a plan he carefully plotted for years, using the death of the Prophet of Regret at the hands of John-117 as an excuse for being supposedly "unfit" to continue protecting the san'shyuum - in reality, motivated by the fact the sangheili started to question the Covenant's war against humanity.

This led the Covenant to fall in disarray, with most of the pursued sangheili siding with humanity and the UNSC to stop the Covenant, after learning their entire religion was false through Arbiter Thel 'Vadam; this uneasy alliance continued after the end of the First Contact War. In the following post-war decade, Arbiter Thel 'Vadam and First Blade Rtas 'Vadum founded the Swords of Sanghelios with those who followed them, establishing a grand council of kaidons, and gaining control of most of the sangheili colonies and many ex-Covenant worlds for their cause, to reform all wrongs done by the Covenant, including the end of the social rifts between its species and peace with humanity. However, they became opposed by many different factions, all who wished to re-start their own version of the Covenant and continue a war against humans and jiralhanae, leading to the Blooding Years, a civil war through sangheili space, as well as the continuing Great Schism against the jiralhanae.

The Ark and reseeding
The sangheili evolved in tropical wetlands of Sanghelios, and were visited by the forerunner in the past, who left numerous artifacts on the planet. During the Forerunner-Xenomorph War, the Librarian visited Sanghelios as a part of the Conservation Measure to save sangheili specimens for the Ecumene, and index them in the Ark so they could survive the activation of the Halo Array. After the rings were lighted and all life extinct, the sangheili, alongside all remaining living species in the galaxy, were returned to their homeworld via Keyships, where they started rebuilding their culture.

Development of civilization and the Covenant
After returning to Sanghelios, the sangheili found many of the artifacts the forerunner had left behind, and started to revere them as gifts from the gods, so much that any tempering with them was considered heretical beyond any other crime. However, many sangheili scientists went against what they saw as dangerous dogmas and secretly studied the forerunner technology, which would later become of pivotal importance into reverse engineering weapons to combat the san'shyuum. Hundreds of years later, the sangheili became advanced enough to reach Tier 3, developing slipspace technology and exploring beyond their home system, colonizing dozens of planets, with Sanghelios as the center of their civilizations' government and cultures. Not much later, numerous sangheili clans started waging war against each other for territory and dominance of the planets, which became known as the Clan Battles of Sanghelios.

War of Beginnings
In 938 BCE, the sangheili made their first contact with an alien civilization, the Reformist san'shyuum, who also worshiped the foreruners as gods, but that used their technology to suit their civilization's needs, believing that such technology was left behind as gifts. This quickly led to a conflict between the two species, the War of Beginnings, which started on the sangheili colony Ulgethon. Despite the sangheili's greater imposing physicality and numbers, the san'shyuum possessed the Dreadnought, which saw the death of thousands of warriors. By 876 BCE, even the most zealous orokin devout saw that if the sangheili were to survive they would need to adapt orokin technology, which saw an uneasy agreement between the two species, with the Dreadnought being deactivated and the two allying into the Covenant.

Their agreement, the Writ of Union, saw the unification of the faith on the orokin status as transcendent beings and the pursuit of the Holy Rings, which were scattered through the galaxy. They believed that, if these rings were reached, they would go into the "Great Journey", which would send them to ascension just like the orokin. Despite this, the san'shyuum still had greater saying on the organization of the Covenant, while the sangheili served as warriors.

Anatomy and physiology
Sangheili are tall, muscular, and imposing standing between 8' 4" to 8' 10" feet, their height making them the third tallest species of the Covenant, only behind jiralhanae and mgalekgolo. They have a unique feature with their jaws being quadruple-hinged, with an upper jaw and four lower mandibles. Adult sangheili's mandibles are observed in numerous shapes, sizes, and ranges of dexterity, which make them analogous and as unique and distinctive as a human fingerprint. Their sense of smell come from two small nostrils, located in front and below their eye sockets, coped with their predatory and carnivorous nature, sangheili make up to excellent smellers.

A sangheili's hand is tetradactyl, with each of them having two fingers and an opposing thumb on both sides. Their legs are digitigrade, with short upper and lower legs, elongated tarsals, with they using the intermediate distal phalanges to support their weight when walking, which allows them to run quickly and jump between large distances, agility that can also be attributed to Sanghelios' high gravity. They also have a double set of pectoral muscles, something which enhances their natural strength, but their digitigrade stance makes climbing ladders and vertical constructs problematic.

Sangheili possess a binary circulatory system, and their blood is dark purple. They breathe oxygen, with Sanghelios having a nitrogen-oxygen based atmosphere, much alike that of Earth. The species has leathery skin that range from light brown to dark brown to brown, to light grey to black, and that are covered in scales. Young sangheili have less, paler scales, which hang from their necks, and which they lose once they reach puberty, in itself a leftover evolutionary trait when sangheili carried their children in their jaws. Their eyes are forward-facing, with vertical slits and horizontal eyelids, resembling that of Earth's reptiles, which grants them an advanced depth perception. Their eyes range from red to green, and even grey, although yellow and orange are the most commonly observed eye color.

Sangheili sexual dimorphism is barely noticeable, with the females only being slightly smaller than the males. However, while a male sangheili's scent is described as "leathery", a female's scent has been described as "clean feathers". The species is oviparous, laying eggs, which are incubated in tanks and pods. Sangheili are long-lived, with some of the oldest known members of the species being one hundred and eighty years. Sangheili in their 60s and 70s are still considered young and apt for combat.