Ultramarines - Specialised Ranks and Formations: Alongside the conventional order of battle with which the Ultramarines operated described above, several unique formations stood wholly apart from the traditional structure:Evocatii - The earliest of these non-standard formations to emerge were the Evocatii chapters, first introduced by Lord Commander Gren Vosotho and later reorganised, expanded and renamed by Roboute Guilliman. The Evocatii was the training ground of the XIII Legion; comprising two double-strength chapters composed of both raw recruits from across Ultramar and beyond, as well as a core of war-hardened veterans. Where the late lord commander had once blooded these neophyte warriors at the forefront of his campaigns, Guilliman assigned them first a tour of defensive operations within the borders of Ultramar in conclusion to a rigorous training regime which favoured both practical battle experience and more rigorous and more lengthy cerebral conditioning and memetic implantation than most other Space Marine Legions undertook.Suzerain Invictarus - The most famed and potent of the XIII Legion's elite sub-formations were the Suzerain Invictarus. Known also as the Invictarii, this was a Veteran cadre who served both as a Legion elite and as a pool of warriors who through their actions had singled themselves out for potential future high command, not simply by bravery or skill at arms, but also for displaying a talent in governance, organisation and administration. Their ranks formed the core outside the usual Legion structure devoted in no small part to the control and order of the Ultramarines writ of domain, and increased in number as the Legion itself expanded and the Realm of Ultramar with it. The Invictarii formed the retinues of the five Tetrarchs of Ultramar, and functioned as both military force for the defence of that fiefdom, arbiters of law for the population and an honour guard for their commanding Tetrarch in battle. The individual forces of these Suzerain Invictarus varied in size, with Tetrarch Amyntas maintaining a force of several thousand as feared peacekeepers in the troubled worlds around Iax, while Tetrarch Lamiad had but one hundred in his guard, partly in deference to the potency of the Mechanicum warriors who stood in Konor's defence and did not need aid in doing so. Outside of the Suzerain forces, members of the Invictarii could also be found in limited numbers spread through the Legion's Veteran units and various sub-stratas of command (although by number only a fraction of all Veterans, officers or sergeants ranked amongst them) gaining further battlefield experience and honing their skills by field command.Fulmentarus Terminator Strike Squad - Created by Roboute Guilliman after observing the Iron Warriors Tyrant Siege Terminator squads in battle, the primarch judged the tactic worthy of refinement. He immediately ordered the creation of a number of similar units in his own Legion so that he might study and improve upon Perturabo's innovation, proving himself once again the master of all of the myriad disciplines of war. The warriors of the Fulmentarus are equipped with Cataphractii Pattern Terminator Armour, enhanced to carry an array of targeting systems that make it possible for each to combine their fire in a highly coordinated fashion. When combined with a heavy weapons system such as a Reaper Autocannon, or the Cyclone Missile Launcher first utilised by the Tyrant Siege Terminators, these sensors make the Fulmentarus a fearsome heavy assault unit and one that, were it not for the outbreak of the Horus Heresy, might one day have entered service across the Legiones Astartes.Locutarus Storm Squad - The Locutarus Storm Squads are elite units maintained in small number by the majority of chapters within the Ultramarines Legion, and deployed particularly in vanguard and strike formations. Each warrior of the Locutarus had been selected from the line assault squads having proven themselves the most skilled, courageous and ferocious of their brethren. Where the assault units of many other Legions were known for their savagery or even their outright bloodthirstiness, the Locutarus were universally iron-disciplined and exacting of mien. They practiced the arts of sword and pistol play with precision, their strikes perfectly timed and placed to maximum effect. In battle, Locutarus Storm Squads were often held in reserves, their commanders waiting until the perfect moment to commit them to the battle, unleashed in one single charge to tip the outcome in favour of the Ultramarines. The Locutarus were superbly equipped to fulfil this role, each bearing an artificer-wrought power sword which served as a mark of honour and courage as much as a lethal tool of war.Vigil Operatii - Though rarely spoken of, there existed another agency of the XIII Legion at work within the borders of Ultramar. The Vigil Operatii, an organisation whose roots stretched back to the early days of Ultramar's founding, operated as a shadow arm of the military government of Ultramar, silencing those threats uncovered within the Five Hundred Worlds and holding custodianship over the various defence militias of its standing Human armies. Little is recorded of their internal organisation, save that the warriors who made up their forces were at their core a body of augmented Humans -- those aspirants whose minor deficiencies of mind or body barred them from joining the ranks of the XIII Legion, but not from service to the primarch and the Emperor. This organisation reported to the Invictarus and went where a transhuman Legiones Astartes could not go covertly or easily, and in its manner may have been patterned at least in some part on the similar operatives of certain other Legions of more insidious mien such as the Alpha Legion, although with an assuredly ironclad code of conduct set for their operations.