Solar Auxilia Tactical Command Sections are specialists in battlefield command and control. Led by a Captain or similar sub-commander, these expert sections facilitate the flow of orders, direct the tercios, and co-ordinate artillery and orbital operations. This vital role is mirrored by the junior Line Command Sections who lead frontline troops, while the most powerful and celebrated officers of the Solar Auxilia, known broadly as Legate Marshals, instead go to war with personal guards equipped from their private armouries.

The Predator is perhaps the best known and most widespread variant of the basic Rhino chassis, equipped with superior armour protection and firepower, but sacrificing the Rhino’s troop transport capacity entirely. The Predator Support Tank is designed to field a wide variety of armament configurations, allowing it to excel in specific battlefield roles.

Veletaris Storm Sections are an elite amongst the Solar Auxilia, assigned the most potent weaponry and the most arduous missions. Deployed as shock troops, their discipline and firepower can overwhelm even the most fearsome of enemies in a storm of concentrated heat rays. Other commanders utilise the Veletarii as a skilled and determined line reserve, able to react quickly to enemy breakthroughs and bolster a wavering defence, or as an axe-wielding honour guard for high-ranking Solar Auxilia officers.

The Horus Heresy is a conflict of unparalleled destruction, spread across myriad vital campaigns. Embroiled for years in a grinding war of nearly unfathomable scope, the Garmon Cluster now acts as the final break against which the tides of the Warmaster’s forces must crash. Its capital, the Beta-Garmon system, is a burning pyre of armies, where Loyalist forces – led by the Great Angel Sanguinius, the Warhawk Jaghatai Khan, and the remnants of the Shattered Legions – fight to buy precious time before the assault on Terra can begin in earnest.

The Leman Russ Strike Tanks fielded by the Solar Auxilia are robust armoured vehicles, augmented with Solar-pattern survival systems that allow both tank and crew to operate in the harshest conditions. Squadrons of Strike Tanks are often used to perform wide flanking advances, guided by a Leman Russ Command Tank in order to engage an enemy at the precise moment the cohort's infantry sections launch their own assault.

The Solar Auxilia are the most elite division of the Imperial Army, mortal soldiers trained to fight in alien atmospheres, toxic death zones, and even the cold vacuum of space – the most hazardous battlefields of the Great Crusade. Equipped with sophisticated wargear and sealed environmental armour, the Auxilia are recruited from across the Imperium's many conquests, chosen for a mix of skill, discipline, and raw aggression. As the Age of Darkness sweeps across the stars, the countless cohorts of the Solar Auxilia must each declare their allegiance – honour their Warmaster, or stand with their Emperor?

Outside the loyalist Space Marine Legions and the Cult Mechanicum, the Emperor wields forces which are loyal only to him. The Legio Custodes guard the Emperor's person, while the Sisters of Silence stand watch over the Black Ships. The Solar Auxilia are the elite spearhead of the Imperial Army, exemplars of mortal soldiery, while the Divisio Assassinorum is the Emperor's culling blade, aimed at the neck of any foolish enough to imperil his grand dream of Unity.

Ahzek Ahriman has the unique distinction of being both the first and last Chief Librarian of the Thousand Sons, and is the most gifted mystic among their already-formidable psyker corps. A respected commander even before his Legion's reunion with its missing Primarch, Ahriman's keen intelligence and talent in warpcraft soon made him Magnus' foremost apprentice, but his greatest strength is his indefatigable will. Ultimately, this determination would see him play a pivotal role in the Burning of Prospero – and walk strange and terrible paths long after the close of the Horus Heresy.

The Solar Auxilia are the most elite division of the Imperial Army, trained and equipped to fight in the most hazardous environments. Their cohorts are recruited from all over the Imperium, drawing on void-born asteroid clans, ambitious noble scions, and underhive scum alike. Whatever their origins, those who display the right combination of aggression, discipline, and skill-at-arms can win glory and greatness by leading the advance of the Imperium's tercios.

The Spartan Assault Tank is a huge armoured conveyer, designed to bear a great contingent of troops into the heart of enemy lines, weathering weapons fire that would be the death of any lesser vehicle. Protected by a sealed shell of legendarily durable plating, the Spartan's carrying capacity exceeds anything but a true super-heavy transporter, while retaining an impressive speed across the battlefield. Its quad lascannons make the Spartan a fearsome tank destroyer, while its secondary armaments allow it to sweep infantry from its path. The Spartan takes pride of place in the armouries of many Legions, its presence limited only by its sheer scale.

The Spartan Assault Tank is a huge armoured conveyer, designed to bear a great contingent of troops into the heart of enemy lines, weathering weapons fire that would be the death of any lesser vehicle. Protected by a sealed shell of legendarily durable plating, the Spartan's carrying capacity exceeds anything but a true super-heavy transporter, while retaining an impressive speed across the battlefield. Its quad lascannons make the Spartan a fearsome tank destroyer, while its secondary armaments allow it to sweep infantry from its path. The Spartan takes pride of place in the armouries of many Legions, its presence limited only by its sheer scale.

The Predator is perhaps the best known and most widespread variant of the basic Rhino chassis. Augmented with superior armour and firepower, it entirely sacrifices the Rhino’s troop transport capacity in favour of ammunition and generators for its formidable weapon systems. The result is an effective and versatile tank of the line, with an excellent balance of speed, firepower, and protection. The Predator's robust design can field a wide variety of armament configurations – the Legiones standard is a rapid-firing turret mounted autocannon, but other configurations include a powerful heavy lascannon, or more exotic grav and volkite weapons.

The Deredeo Dreadnought is a walking heavy weapons platform, designed to combine superior firepower with the flexibility and durability of a Dreadnought chassis. Though highly resource-intensive to produce and maintain, its undoubted survivability and killing power ensures the Deredeo is in high demand by Traitor and Loyalist Legions alike from the few Forge Worlds able to fashion them.

Sky-hunters are feared strike units, mounted atop sophisticated and powerful jetbikes. These high-speed craft are more akin to compact aircraft than ground bikes – propelled across the battlefield by jet engines with grav-impellor assistance, they can maintain great speeds for extended periods of low-altitude flight. The jetbike's lift-strength is enough to carry an armoured Space Marine and his wargear along with a variety of heavy weapons mounts and stocks of ammunition, giving the Sky-hunters access to extremely potent, highly mobile firepower.

The Knight Questoris is the most prominent variety of Knight Armour on the battlefields of the Horus Heresy, striding forth alongside the Legiones Astartes, Taghmata Omnissiah, and in the great armies of Knight Households. Such was its popularity amongst the noble scions of the Questoris Households that it was reconfigured in myriad ways with weapon options and hull augments, and given names such as Paladin, Errant, Warden, Gallant, and Crusader to reflect their traditions, lineage, and fighting styles.

Heavy Support Squads provide the Legiones Astartes with mobile, infantry-portable firepower sufficient to bring down hordes of enemy troops or smash armoured vehicles apart with withering hails of fire, combining devastating armaments with all the flexibility of a footsoldier. Volkite culverins emit scorching heat rays that burn through swathes of infantry, while versatile autocannons spit shells that shred troops and light vehicles alike. Lascannons are the most powerful laser weapons available to Legionaries, firing devastating beams to punch clean through tank armour.