Heretics (Faction)

The Heretics were a faction of Elites and Grunts who broke away from the Covenant after The Battle of Installation 04.

Origins
Originally a Covenant artifact retrieval team attached to the Fleet of Particular Justice, the faction of Grunts and Elites now dubbed "Heretics" and led by Sesa 'Refumee were investigating a Gas Mine on Threshold when the UNSC Pillar of Autumn crashed on Installation 04. When the Master Chief destroyed the Halo, the team was spared from death.

A few days later, the Monitor of Installation 04, 343 Guilty Spark, arrived at the gas mine. He promptly took command of the Sentinels running the facility, and began informing the artifact retrieval team of the true purpose of the Halos, destroying their faith in the "Great Journey."

Disillusioned with the lies of the Prophets and their Great Journey, Sesa 'Refumee began open rebellion. He sent holographic recordings to other Elites hoping to open their eyes as well. In the meantime, he strengthened the defenses of the Gas Mine, fortifying it with Plasma Cannons and a large compliment of Banshee fighter craft. He also had at least one Seraph fighter.

It is unclear how many more Elites 'Refumee was able to sway to his cause, but his significant military force and strong words attracted the attention of the High Prophets, who decided to put the "Heretics" down with two other former commanders of the Fleet of Particular Justice; the disgraced Arbiter and SpecOps Commander Rtas 'Vadumee.

In the meantime, the Heretics on the Gas Mine discovered that the facility was refit into a Flood Research Facility when they accidentally released the Flood upon themselves. They began a battle throughout the entire mine to contain and destroy the Flood.

The Arbiter and Rtas 'Vadumee arrived at the facility with three Phantoms full of Special Ops Elites and Special Ops Grunts and, despite heavy resistance from the Heretics and the Flood, were able to kill Sesa 'Refumee and destroy the gas mine completely.

This was a crippling blow to the Heretics as a faction. It is possible that some survived though, as Halo 2 Multiplayer maps states the Heretics operated a base on Basis as well.

Appearance
Having abandoned the ideals of the Covenant entirely, Sesa 'Refumee decided to carry a new banner for his troops; the beige and gold colors of the Sangheili homeworld. The Elites and Grunts donned new armor of these colors as well as outfittings to help them survive in the Hydrogen atmosphere of the Gas Mine.

The Heretics also changed the appearance of their vehicles; the Heretic Banshees and Seraph had much of their external plating ripped off, revealing the Forerunner based workings within. They were also repainted to bear the colors of the Heretics and the Sangheili world.

Heretics only appear in two levels, The Arbiter and The Oracle.

Heretic Grunts
Heretic Grunts wield Needlers, Fuel Rod Cannons, and they can also man Plasma Cannons. They have never been seen using Plasma Pistols, the weapon more commonly used by their regular, non-Heretic counterparts, although a fair amount of Plasma Pistols are scattered throughout their base of operations. They are also not as suicidally stupid as their Covenant counterparts, and they never panic or run away. They are also noticeably tougher and harder to melee due to their reduced armored re-breathers. Their mask do not cover their entire mouths as those of Covenant Grunts do.

Heretic Elites
Heretic Elites seem to use either Carbines or Sentinel Beams and occasionally the Energy Sword. This probably means they use reloadable weapons instead of making multiple weapons. Apart from the Heretic Leader himself, they never use the Plasma Rifles wielded more often by their regular counterparts, although if you board a Banshee piloted by one, the pilot will be wielding one. Heretic Eliteshave three ranks. Brown Elites are the equivelent of a loyalist minor-Domo. the gold. The red armor is only worn by the Heretic leader. They use what they steal when they defect, or they utilize what they find and scavenge. A strange and serious glitch causes their melee attacks to have no effect.

Trivia

 * Bungie considered making the Heretics in Halo 2 mostly Hunters, but was obviously never followed through on.