The Hand of Tonitrui is the small splinter faction of the Covenant lead by Sotophirus. The faction, similar to the Storm, still believe solely in the Covenant tradition observed during the Human-Covenant war. They were a relatively newly encountered faction, but were still quite formidable.
Originally, the faction was simply a group of high-end Brutes trained by Tartarus that didn't have an official name; Sotophirus was a significant member since the group's founding. These Brutes were some of the most elite Jiralhanae in the entire Covenant empire.
Eventually, the group was well regarded for their work on Harvest, and several other fronts, including Reach. However, Sotophirus was not on Reach with this faction during the time; it was only until later, when the group became a secondary branch faction in the Covenant military, did they regain their leader in battle. Their most significant role was during the battle of Installation 05, when Tartarus sent them to assasinate several Elite councilors along with other teams of Jiralhanae. They managed to slaughter almost 2 dozen Councilors, who are themselves formidable opponents and the highest-ranking Sangheili, before their first encounter with the Arbter. Most of the team was killed or severely wounded by the skilled warrior; however, a badly wounded Sotophirus managed to escape and enter one of the remaining loyalist ships that fled the Forerunner construct and the ensuing battle. He took that ship back to Doisac, the Jiralhanae homeworld, while the rest followed the Prophet of Truth back to Earth. Sotophirus reestablished his group, and named it the "Hand of Tonitrui", after one of the legendary Gravity hammers of Jiralhanae lore. 2 years later, after the Human-Covenant war, his faction, still young and growing, was caught in a skirmish with a UNSC fleet; with only 3 ships at their disposal, Sotophirus' group managed to deal a devastating blow to the human force 5 times larger than their own. This was the last time the faction was seen, and during a ground conflict initiated after one of the ships crash-landed on Doisac, he was seen wielding the legendary hammer and donning his current, highly-protective armor. They captured Danno at some point. The Spirit of Fire, Genesis, and CMF, with assistance from Exon and Bad Company units, went to rescue him, meeting intense opposition.
Jiralhanae- As in the Covenant Loyalist empire, the Jiralhanae are the leaders of this faction. Pack leaders give overall command during battle, and most, if not all of them, wield Brute technology and nothing else. Many of these Brutes were trained intensively at a young age, similar to the Spartans of the UNSC, making them stronger than most Brutes. Some Brutes are even lightly augmented with covenant technology, serving as the special forces units. The Jiralhanae also serve as ship masters and vehicle/aircraft drivers/pilots.
Unggoy- As in the original Covenant, the Unggoy in this faction are used mostly as cannon fodder, and also are the highest numbering in the faction. Unggoy in this faction are more aggressive than those even in the Covenant loyalist empire, and more ferocious; they will more often go suicide and take entire squads of enemies with them than ever before encountered with normal grunts. Unggoy in this faction specialize in attacking en masse, overwhelming their enemies with sheer aggressiveness and brutality.
Kig-Yar- Even though this species has a smaller number of units in the faction, the Hand of Tonitrui still utilize a number of them as scouts and fast attack ranged units. These Jackals are so ravenous, they are known to sometimes revert to attempt to swarm individual or groups of enemies, and consume them.
Hurragok- These Engineers were grown artificially for one purpose: Serve the Jiralhanae. They have no other function than to repair equipment, forge weapons, and even assist in combat. Unlike Hurragok encountered before, these Engineers are actually outfitted with weapons, and will attack enemies with extreme aggression.
MgaLekgolo- Though most of the Hunters joined the Covenant Separatists, there were plenty that remained loyal to the Prophets, and a fraction of them were handed over to this faction. Those encountered in this group are extremely aggressive, are seen in a variety of ranks and shades of color in armor, and even can be observed operating in groups of four.
Sangheili- Recently, Outposts belonging to the Hand of Tonitrui have been observed using Sangheili as a sort of worker role. Most of the Sangheili seen appear to be either very young or very old, very few of them being female. They are outfitted with standard slave-worker outfits, often operating in groups of 3-5 or up to 7, watched by a Brute Captain, who wields the Jiralhanae equivilent of a laboring whip. These Sangheili are obviously not willingfully working for the Jiralhane as they have a deep mutual hate for each other.
Yanme'e- The only purpose the Drones fill in this faction are for Base defense; they are almost never seen in forward combat. However, Bases belonging to this faction are known to have up to two hives of Drones nearby, capable of being called upon for near-instantaneous defense.
The faction is spread in a small sector across old Covenant Space; the center of their territory could be anywhere within a 5-system radius picked up by leaked information from an unknown Elite. Further study is required, study initiated on the UNSC station "Reservoir", located on the planet Reach. It is believed this was the station that discovered the relative center of this faction's territory.