Now that I have my own Thallax Cohorts, I thought I should do an article in detail about the difference between the Thallax and the Skitarii. Both are the core infantry forces of the Mechanicum and Adeptus Mechanicus militaries, but while the latter was widespread during the 41st millennium, that was not always the case during the Great Crusade - thus, the need for the various Taghma and militant arms of the Mechanicum to raise their own infantry. Indeed, the Ordo Reductor created the Thallaxii to replace the Skitarii Legions of Mars, because they had no direct or ready access to the Skitarii for support.
The Thallax are specialized cybernetically augmented Mechanicum shock-troops manufactured and principally used by the Ordo Reductor, which we know from previous articles are the "Bringers of Blessed Ruined" and worship the Omnissiah in His aspect as the Destroyer and bringer of oblivion. Unlike the Skitarii regiments, the Thallax have a much higher degree of augmetics and serve as shock troops, specializing in spearheading assaults, close-range firefights and overwhelming force, rather than the more diverse roles of the Skitarii, who are more suited for holding ground, scouting and providing support to heavier combat elements.
Designed to operate in the most lethal and hazardous theaters of war, the Thallax is a bridge between the more commonplace heavy combat servitors, such as the Kataphron-class, and the the augmented human Skitarii of Mars's legions.
Thallax are encased in the Lorica Thallax, which is developed from the same power armor technology utilized in the development of Legiones Astartes battle plate and shares many common components, especially with the early patterns. Both Legiones Astartes power armor and the Lorica Thallax are extremely adaptable and highly durable, and the latter provides great strength and resilience for the Thallax on the battlefield. This also allowed a beneficial degree of cross-supply between the Legions and the Ordo Reductor during the Great Crusade. Unlike the power armor, the Lorica Thallax is permanently surgically bonded to the body of the wearer and uses linked mechanical armatures to replace the primary limbs.
The Lorica encases the major organs, nervous system and cerebrum, but replaces the skeleton and limbs entirely with armored mechanical systems powered by an internal reactor-core. Only the brain, skull and spinal column are retained, the life-sustaining viscera and nervous system as a basis of the articulated and armored robotic frame that encompasses it. The armor is fused directly to the spinal column and nervous system of the Thallax and marks them both as warriors of the Mechanicum and a symbol of their servitude. Human sensory systems and organs are also completely replaced by augmetics, but apparently, the surgical process is so excruciating that they need to remove pain centers and emotions.
Uh...duh? Any surgery of that magnitude would be excruciating. I'm pretty sure the surgical process for the Skitarii should be similarly painful, though, as stated, the Thallax are more advanced in augmentation. That probably explains why they...uh, Feel No Pain. At least in the current 2.0 edition.
Anyway, the Thallax still retains a degree of independent human thought, which...is basically the same as the Skitarii. However, because of the excruciating process, there is a risk of the poor subject going insane, and apparently it requires quite a lot of resources. That doesn't matter, because apparently, during the Heresy, you have millions of these guys running about, though I suspect the original intention was for them to be rarer than even Legiones Astartes. They originally cost 135 points for 3 dudes, and now 125 points, base. Compare that to 110 or 100 points for a Tactical squad of 10 legionnaires.
Consequently, Thallax conversion is reserved for suitable Forge Guard and Skitarii fallen in battle.
The high-energy compact reactor system is so powerful that its emanations cannot be endured by a less augmented organic system, such as presumably the Skitarii. But it is capable of powering extremely potent portable weaponry and arcane implanted sensory apparatus that operates outside the usual realm of organic perception.
Not sure why the living components will be subjected to continuous agony when the pain centers have already been excised, but grimderp...grimdark, I guess. The psychotic breakdown, though, I understand, because the brain's emotional centers have been removed. The cyborg is capable of far greater tactical flexibility and independent action than a servitor, but his psyche will inevitably deteriorate over extended periods of time.
The Thallax are equipped with the Incunabulan Jet Pack. Capable of granting the hulking Thallax a maneuverability that belies their bulk, these jet pack systems are superior to the simple jump packs used by other Imperial armies. It essentially allows the Thallax limited flight capability.
While the Thallax is created exclusively by the Ordo Reductor, they often gift them to other factions such as the Legio Cybernetica for fealty, aid or supplies. Thallax are the most widespread of the Ordo Reductor's creations. As well as serving first and foremost as the Ordo Reductor's line soldiers, the extremely potent and durable Thallax are also gifted and traded by the Ordo Reductor magos to other Mechanicum factions as the Great Crusade went on, most notably to the Taghmata of Forge Worlds and outposts that were far separated from Mars, elements of Legio Cybernetica and the Myrmidon sub-cult in return for reciprocal agreements of supply and allegiance. This served to both greatly increase the power and independence of the Ordo Reductor and probably contributed to the waning of Mars's direct military control over its outlying Forge Worlds in the decades before the Horus Heresy.
Many variants of the flexible and powerful Thallax have been brought to being by the artificers of the medicant Ordo Reductor, a number of which found their way to the outer Forge Worlds of the Imperium where they were seized upon as potent war machines which, while lacking the power of true battle-automata, were far more practical to produce in larger numbers.
The Thallax's lightning guns serve as their primary armament and take the form of a baroquely designed carbine connected to their cybernetic reactor core. It fires an ionizing las-beam down, which a powerful phased discharge of electromagnetic force is unleashed, and is equally effective at slaughtering the living and overloading machine targets.
Specialist gunners in the cohort can also replace their lightning guns with more exotic or powerful weapons, such as the more common multi-melta that is usually mounted atop vehicles as an anti-tank armament, or rarer, more sophisticated plasma weapons - specifically the phased-plasma fusil. Unlike in the 41st millennium, the technology of Imperial plasma weapons was far better understood during the dawning age of the Imperium if still somewhat unsafe.
They can also wield Photon thruster cannons, a specialized weapon usually used by the Mechanicum's Myrmidon Destructors, but also provided to the Ordo Reductor and subsequently their Thallax cohorts. The arcane secrets of these deadly beam weapons are jealously guarded by the adepts who hold them, even from their own brotherhood. When fired, they unleash howling, needle-thin beams of utter blackness able to pierce the densest matter. These tenebrous beams slash and slice armored men and machinery alike like razors, leaving pulsing waves of darkness in their wake.
However, the exotic power sources of these unearthly weapons, even when linked to the Thallax's reactor core, are extremely unstable and little understood by even the Myrmidons themselves, and catastrophic failure can lead to its firer being consumed by raging black flames until only dust remains.
The Skitarii, on the other hand, are less augmented than the Thallax, but they are still cybernetically augmented infantry. Ceramic valves and adamantium sockets stud hard knots of pallid, translucent muscle, much of their flesh is replaced by titanium and their limbs replaced with alloy protheses. Their brains are hybrids of gray matter and twisting neurocircuitry.
Skitarii Alphas are more machine than flesh, overseers who can operate independently for years if necessary, and lead their squads in absence of their Tech-priest masters. Due to their extensive modification, the Skitarii can excel in almost any environment. Each Skitarii Legion hails from a hyper-industrialized Forge World, with many able to withstand lethal doses of radiation and toxic terrain.
Skitarii have their eyelids removed, goggle-like augmetics sealed into place to protect their sight and allow them to continually harvest data. Sophsticated targeter arrays are also woven into them. They are implanted with cognis rebreather tubes that filter the air that enters their lungs, and if necessary, draw upon a reservoir of gases in the void.
They are clad in blessed raiments that are lined with tiny leaden speech-spheres that absorb harmful energies. Skitarii warriors are protected by armored plates designed to be worn for several years at a time, usually referred to as Skitarii war plate. Secreted under a superdermal layer of ceramite alloy are recombinant cells that harness moisture from the wearer and recycle it. This liquid is transmuted into a gelatinous unguent that coats the inside of the suit, preventing the slow abrasion of the wearer's body whilst affording a measure of protection from the harmful emanations of their weaponry.
The Skitarii Vanguard, known informally as rad-troopers, are capable of enduring baleful energies and even weaponizing them. A high volume of radiation bleeds from their wargear, and even the Vanguard troopers themselves are condemned to a slow demise from their signature rad-carbines. Hyper-irradiated shots from these deadly weapons ensure that even a usually non-lethal wound will eventually kill the target, the rad-troopers laying down precise rad-volleys in the most hazardous warzones throughout the galaxy.
Skitarii Rangers serve as relentless hunters and scouts, often armed with more esoteric weaponry such as electricity-powered galvanic rifles and disruptive arc rifles, or even the colossal-ranged transuranic arquebus.
Radium weapons, wielded by the Vanguard, are so volatile that they eventually kill their wielders. Their baroque beauty belies a singularly vile function - rendering the battlefield as deadly as the rad-wastes of Mars. Each weapon's bullet cylinder is so thoroughly bathed in radium that a volley can cause a localized rad-storm. Those inside soon find their flesh blackening and sloughing away.
Modeled after the hunting flintlocks of Mars's past, the Mk IV Arkhan galvanic rifle is a precision tool in the hands of a Skitarii Ranger. The galvanic servitor-bullets inside are incredibly advanced, and when striking home, they cause the potential energy fo the target to burn out in a killing blast of electric force.
Arc weapons, such as the arc rifles or the arc pistols wielded by Skitarii Alphas, are powered by bulky permacapacitators, zinc-plated blocks that store energy. They discharge with a loud crack, firing bolts of blue-white electricity that can fry a man's brain or overload a war machine's datacortex in a second. Basically an electromagnetic pulse.
The transuranic arquebus is a long barreled heavy weapon that embodies percision and inhuman efficiency, a sniper rifle that fires a shell of depleted transuranium. The arquebus can puncture a tank from one side to the other, the resultant pressure wave also pulping any biological creatures that may be sheltering inside.
Unlike the phased plasma-fusil wielded by the Thallax during the Great Crusade and Horus Heresy, the Skitarii of the 41st Millennium are instead equipped with plasma calivers. As volatile as it is deadly, the plasma caliver exchanges range for a truly terrifying rate of fire. That...might have changed in later editions, though, as they now have the same rate of fire as a plasma gun in rapid fire range, but at a larger range. A great example of a retcon, I suppose.
The Thallax and Skitarii fulfill different roles - the former serving as manuverable shock-troops with heavy firepower and durable linebreakers, and the latter a more versatile infantry formation that can scout, hold ground and provide support. While the Ordo Reductor meant for the Thallax to replace the Skitarii, which they were denied access to, they appear to be more akin to the Legiones Astartes in terms of role, size and durability. They have their differences, but that owes more to what they are designed for. The Thallax require more resources to produce, due to their more advanced augmetics and sophisticated technology, but the Skitarii are also bestowed cybernetic implants and esoteric weaponry that raise them above the common soldier of the Excertus Imperialis, while being produced in vast numbers enough to be considered expendable by their Tech-priest masters.
Arguably, an individual Thallax is superior to a single Astartes Legionnaire, being more resilient and possessing far heavier firepower and maneuverability, but the Legiones Astartes operate in squads, which make them as effective as a cohort of Thallax. The Skitarii, on the other hand, have the advantage in numbers, often outnumbering squads of Marines at the regiment level, but are less durable, though wielding comparable weaponry with equally impeccable precision.
