Covenant Empire

The Covenant Empire is a fictional theocratic military alliance made up of multiple alien races and serve as one of the main antagonists of the Halo franchise. They are united under the religious worship of the Forerunners and their beliefs that Forerunner ringworlds known as Halos will provide a path to salvation. After the Covenant leadership, the High Prophets, declare humanity an affront to their gods, the Covenant prosecute a lengthy genocidal campaign against the technologically inferior human species.

Prophets (San Shyuum)
The highest caste, the Prophets lead the Covenant and exert complete control over all religious and political affairs. Though physically weak, Prophets wield power through absolute command of the Covenant and through scavenged Forerunner technology, leaving the task of conquest to the Elites and the other races. Their higher understanding of the Forerunners gives them great ego and religious influence over the Covenant. They were primarily designed by Shi Kai Wang and Eric Arroyo and their characters were also designed to be feeble yet sadistic. The three High Prophets were each individually designed.

Elites (Sangheili)
The second highest caste, Elites served as the military leaders of the Covenant before their betrayal at the end of Halo 2, where they served as the allies to the humans in ''Halo 3. ''While Prophets often had the final say, it was the Elites who organized military campaigns and naval engagements. They maintain the military structure of the Covenant and ensured the Prophets' orders are followed, as well as their own. Elites consider the other client races to be below them in every way and they are also separated into ranks based on skill and experience. To advance in rank, Elites must honorably earn such advancements on the battlefield. They are the strongest and toughest allies and enemies, standing around 8 ft 0 and feature recharging personal shields.

Rank Structure:

Brutes (Jiralhanae)
One of the newer species to the Covenant that first appeared in Halo 2 and are the only race that has obtained a very close equal status to the Elites. They are very strong, tall and resilient due to their tough hides as well as letha technology despite being primitive compared to other Covenant technologies. In addition to their standard form of combat, Brutes can go beserk and try to kill anyone or anything in their path with aggressive melee attacks. Their society is organized around tribal chieftains and when the Elites were ultimately betrayed, Brutes replaced them as the main enemies and military leaders as well as the protectors of the Prophets in ''Halo 3. ''The Brutes always work in packs of 3-8 when possible.

Engineers (Huragok)
Engineers are actually an artificial species created by the Forerunners that were to appear to Halo: Combat Evolved, but were pulled out, and later appeared in Halo Wars, Halo 3: ODST and ''Halo: Reach. ''They will only converse with the Prophets or individuals who learn their language, indicating they are very high in the caste system however they were also believed to be prisoners or slaves of the Covenant. Engineers serve no actual combat role however they were deployed on the battlefield to serve as repair workers or suicide bombers as well as providing shields to their Covenant allies.

Hunters (Mgalekgolo)
Hunters are collectives of worm-like creatures called Lekgolo encased in tough armor and they always fight and travel in pairs, being the strongest of the Covenant fighting units. They wield powerful assault cannons and a massive shield used to protect against enemy gunfire and a dangerous melee weapon with sharp sides. They are usually used as weapon platforms and are only deployed when in need of a heavy force, being utilized more like heavy duty equipment than actual soldiers.

Drones (Yanme'e)
Drones are flying-like creatures that first appeared in Halo 2 and the animators found these aliens challenging, as they animated them to walk, run, crawl or fly on multiple surfaces and old concept art from Halo: Combat Evolved were re-purposed in influencing the Drone's final shape, which took cues from cockroaches, grasshoppers and wasps. They serve almost exclusively as the Covenant's engineers but were replaced by the Engineers, so the Drones were used as aerial combatants instead. Their ability to fight on the wing and their usual deployment in large groups, made them an excellent strategic weapon against ground-based opponents.

Jackals (Kig-Yar)
Due to their superior senses, the Jackals served as the scouts and marksmen of the Covenant military, being the second lowest Covenant caste. Due to their lack of physical durability, they carry portable energy shield generators during combat. Jackals are employed mainly as sharpshooters with their excellent vision and dexterity, and are also deployed to defend strategic areas.

Rank Structure:

Grunts (Unggoy)
Grunts are the most common and lowest-placed caste of the Covenant. Grunts had little choice to accept entry into the Covenant or otherwise risk extinction, essentially becoming a slave race. They serve as cannon fodder, being depicted as squat and cowardly fighters, panicking and running if their leader is killed. Grunts are methane breathers and thus must wear a large tank on their back full of the methane to survive on other planets.