Jaghatai Khan - Emancipation of Drune: By the latter years of the 800s.M30, the Vth Legion had earned itself a reputation for the types of operation for which it would later become most well-known, but not all of its wars were fought in isolation. At Tarel III, Jakor-Tal and Terlaken B3, the Legion fought noted campaigns as part of combined Legiones Astartes Expeditionary forces, and at Arco took its place in the line with the Blood Angels, Ultramarines, Salamanders and Emperor's Children Legions. Indeed, the battle honour "Arco" would be borne on the banners of all five Legions, including the treacherous sons of Fulgrim, throughout the Horus Heresy and well into the latter age of the Great Scouring.Another battle honour borne with pride long after the outbreak of the Horus Heresy by Loyalist and Traitor alike was that won at Drune in 881.M30, a lonely, arid world spinward of the Morpheus Rift. At Drune, the greater part of three entire Legions stood together, each headed by their Primarch.The Imperial Compliance of a world that had once been a beacon of civilisation was to be a crowning glory to an otherwise fruitless expedition, and so the Primarchs of all three Legions present -- the Luna Wolves, the Death Guard and the White Scars -- determined to deliver the Imperial Truth in person. Three entire Legions made planetfall as one, but what transpired when they came to stand before the gates of the world's capital was quite unprecedented in the decades of the Great Crusade.Those gates remained barred, and no reaction to the massing of three Legions before them was forthcoming. His choler rising, Horus raised his mace as to strike the mighty gates, but before he could do so, a word of caution rung out from the throng of counsellors and attendants. The warning had been voiced by Kulek Senn, a senior Stormseer of the Vth Legion."The shadow hangs over this place. The shadow of domination. Only death will sever the strings."Mortarion counselled Horus to press onwards, discounting the Stormseer's warning, and press onwards Horus did, striking the gates such a resounding blow with his mace that it caused them to buckle inwards and collapse with a billowing cloud of dust. Advancing within the city, a great mass of humanity pressed in from every quarter. The eyes of the occupants were unfocused and vacant, every mouth slack and drooling. Every body was unwashed and stinking and clad in shredded rags, as if the wearer had given no thought to their own bodily well-being for many solar months, perhaps even years.Once more, Kulek Senn offered his master his warning as the party moved through the streets, this time with increasingly strident concern. Once more, Mortarion heard and sneered his derision of the psyker's arts, but this time the Great Khan interjected, insisting that his brother Horus heed the Stormseer's words.This time, Horus did so. Whatever it was that the Stormseer had detected an echo of before the gates was now evident for all to see. In the heavens above, a churning vortex of unnatural energies was forming, its eye directly above the centre of the city. Aetheric gusts caught the Primarchs' personal banners and the massed bodies finally stirred, a deep, sonorous groan voiced simultaneously from 100,000 throats.Fighting their way clear, the Primarchs reunited with their gene-sons outside of the city, and in council with the Great Khan's Stormseers they determined that the entire world was under some manner of xenos domination, one born not of physical reality, but of the other-realm of the Warp. Worse still, they counselled that this domination was being exerted upon the human population of Drune via a series of extradimensional portals, each centred upon one of the major mesa-top cities. Only by closing these portals, the Stormseers claimed, would the enslavement of Drune be ended.And so the war to deliver Drune from the yoke of alien domination began. Jaghatai Khan was nominated by Horus as campaign commander. Such a thing was rare indeed, for even though the Emperor's gene-sons fought beneath the same banner and the sundering of their ranks was still many solar decades away, there existed a deep-seated rivalry between many.The wisdom of the Lupercal's decision was plain to see, but the Primarch of the Death Guard Legion protested it nonetheless, for Mortarion detested the employment of psykers in any form, for any reason and against any foe. Thus the Death Guard served in the Drune campaign only nominally under the Great Khan's leadership, Mortarion ensuring they remained apart from the other two Legions.The war for Drune would rage for almost six Terran months, the Great Khan utilizing each element of his command as best suited its nature. Jaghatai's own Legion ranged far and wide across the wastes of Drune, striking at concentrations of xenos power identified by his Stormseers. They encountered a range of horrifying creatures of barely definable form, though all had in common bloated bodies that floated on invisible aetheric tides, multiple eyes, thrashing tendrils and the ability to unleash fearsome blasts of Warp energy even as they directed wave after wave of sub-human mind-slaves at the Legionaries.The Stormseers proved crucial not just in locating these abominable foes, but in combating them on the field of battle too, for they were able to deaden the psychic domination effect and thus allow their brother Legionaries to engage the xenos puppet-masters and defeat them, albeit not without loss.At the last, the campaign reached its climax where it had began -- at the mesa-top city where the three Primarchs had first encountered the xenos dominators. The closer to the heart of the city the Primarchs advanced, the more potent the psionic waves assaulting them grew, and the more massive and hideous the xenos abominations they encountered.Though a potent force indeed, none can say what harm might have befallen the Primarchs had the White Scars Stormseers not been close at hand to repel the worst of the aliens' psychic counterassaults. The air itself screamed in torture as the very stuff of reality was stretched to breaking point, the un-light of the Warp glimmering through a million cracks and rents.Jaghatai, Horus and Mortarion knew that they had reached the centre of the xenos incursion when even they could proceed no further, so powerful were the psionic tides flooding out from the hideously pulsating wound in reality at the very centre of the city.Overhead loomed an archway of the quivering, still-living flesh of what must surely have once been a man. Beneath the archway was a void pulsing with the raw power of the Warp, and from it was emerging a vast and bloated form, a distended central sac replete with thrashing pseudopods and dozens of too-knowing eyes.Voicing an ancient Chogorian curse, the Great Khan swore the behemoth would not establish dominion in his gene-father's realm, and in answer, his brothers took their place on either side while what remained of his depleted Stormseer council formed a loose ring all about, every last iota of their power bent to the task of warding off the behemoth's vile kin.Scholars of war might ponder what force might test the powers not just of one, but of three of the Emperor's gene-sons, and in the contest that ensued they might find one such possible answer. The behemoth brought to bear an array of weaponry, from whipping, diamond-sharp tentacles to the unrelenting power of its utterly alien will -- 10 Stormseers lay dead upon the ground in as many seconds, their minds torn apart by the behemoth's battering ram of psionic domination.The Primarchs were sorely tested, for while such as they could scarcely know fear, each soon bore a dozen and more hurts. Even the mighty Horus felt the behemoth's mental whip, and though he repelled its will, the effort left blood gushing from his eyes in crimson rivers.Mortarion too struggled against this vile foe, and while his scythe cut through its thrashing tentacles by the dozen, it strove to gain dominion over his mind and to become master of his flesh. As with Horus, the behemoth was unable to batter down Mortarion's defences, but resisting it drove the Death Lord to his very knees.It was Jaghatai Khan who at the last put an end to the xenos beast. By the combined efforts of his last remaining Stormseers, the Great Khan was rendered unseen to the behemoth, so that even as it concentrated its assault upon Horus and Mortarion, Jaghatai was able to work his way around the creature's vast, bloated form and thereby locate a weak point upon its underside.Many Imperial savants now wonder how different later ages might be had only Jaghatai stayed his final strike or but delayed it long enough for the behemoth to press its assault upon his brothers. Such ponderings are of course futile, and they ignore his essential nature. Jaghatai thrust upwards, spearing some essential node or organ in the behemoth's central mass. It died upon his blade, but the explosion of aetheric force unleashed was very nearly his end too.It was Horus who saved Jaghatai from being sucked into the now collapsing vortex, Lupercal hauling his brother clear. And thus was the Emancipation of Drune achieved -- though not a single one of the world's populace would benefit from the defeat of their alien masters.With the behemoth slain, and the Warp portals through which the aliens had exerted their domination sealed, hundreds of millions of meat-puppets collapsed wherever they were standing, never to rise again.In truth, such a fate was a mercy for the people of Drune and for the Imperium, for one way or another, they could not have been allowed to live.