Editing Onyx the Indestructible (section)

===The Hektor Heresy===
[[File:Parthorumstream.jpg|200px|thumb|right|Diagram showing the warp currents of the Parthorum Stream, its key worlds, and Sol.]]
When Onyx heard of [[The Voidwatcher]]'s treacherous attack on Terra, he immediately set aside his other business and took his 44th Expedition Fleet to the Loyalist rendezvous at Diamat. The 44th would have a long journey to Diamat and Onyx considered it likely that the battle for Ostium would be long underway by the time of their arrival. However, he felt that the Voidwatcher would not have been so brazen as to betray the Imperium without some kind of plan and was determined to provide assistance if the [[Iron Rangers]], [[Scale Bearers]] and [[Thunder Kings]] were unable to breach Ostium's defences. In truth, Onyx was too optimistic. On his arrival at Diamat a wave of psychic anguish washed over the Stone Men psykers and Iron Rangers warships were picked up fleeing the system. Despite the Stone Men setting off at a reckless pace, they were unable to catch the Iron Rangers fleet before the traitors jumped into the Warp.

Onyx gathered his fleet together and returned to the inner system to provide assistance to the Scale Bearers. He was horrified to learn that the pyschic emanations were caused by the death of [[Tiran Osoros]] at the hands of the Iron Rangers Primarch [[Rogerius Merrill]] and greatly disturbed to find many of Tiran's gene-sons struck mad by the death of their sire. After signalling Terra with the grim news Onyx did what he could to help Rychad Owain regroup the surviving Scale Bearers. These comradely efforts had to be set aside when Onyx had a brief but unmistakable vision of his brother, Shakya Vardhana. The apparition spoke only the word ''Kuniat'', imploring the Stone Men to take action. Such visitations had played an important role in the Kolossomachy and though Onyx did not know why the Stone Men were needed so close to Terra he did not doubt the Vardhana. As the 44th Expedition Fleet moved out of the Diamat system, Astropathic communications from Terra explained that [[Hektor Cincinnatus]] was in revolt and leading his Legions towards Sol. The vagaries of Warp travel can make a mockery of precise planning, especially when fleets must move over long distances. Onyx's fleet arrived at Kuniat to find the system in Hektor's hands and Traitor warships massing for their final assault. Never doubting the need for heroism against great odds, the Stone Men carried out a swift hit-and-run raid on Hektor's fleet. While Onyx's capital ships engaged the Traitor line, his escorts slipped in to wreak havoc among the amassed macro-transporters. At the end of the short engagement, the Stone Men withdrew towards Terra knowing that they had struck a major blow against the Traitors at little cost to themselves.

On their arrival in humanity's birth system, the 44th received a mixed reception. Many of the ordinary soldiers of the Imperium were delighted to see them, including Shakya Vardhana and his Eyes of the Emperor. Alexandri of Rosskar, now acting as Warmaster of the Loyal Forces of the Imperium, was more sober. In a short holo-council of war, major differences of strategy emerged. Alexandri openly mocked Onyx's plan for a counter-offensive and the two might have come to blows had they been in the same room. Shakya Vardhana managed to ease the tensions and a compromise plan was agreed, with Alexandri's [[Silver Cataphracts]] and the Eyes of the Emperor remaining in the Sol Sector to protect Terra while the Stone Men travelled out to recruit the as-yet undeclared Legions.

While they were hardly friends, Onyx first set out to call Tollund Ötztal to war. On arrival at the Mastodontii Homeworld of Tisenjoch, the Stone Men were hailed and informed that the Eighth Legion was deep in mourning for the blood already spilt among the Space Marine Brotherhood. The warriors of Tisenjoch would make no decision until their rites were finished. This flimsy excuse was dismissed with contempt. Onyx demanded that the Mastodontii set aside their sham neutrality and declare for the Imperium in accordance with their vows of loyalty. After twenty-four hours of silence, the Stone Men realized that they were being played for fools and launched an attack on Tisenjoch to cripple the Traitors before they could finish their preparations for war. While the landings went well, the monstrous face of treason was soon on display. The Mastodontii committed a series of atrocities against their own civilians, starting with human shields and ending in the very depths of depravity. After three months of campaigning, in which Tisenjoch's key facilities were crippled and much of the Eighth Legion's heavy equipment destroyed, the Stone Men withdrew from that accursed world and set a course for [[the Atalantos Worlds]] where they hoped to link up with [[Arelex Orannis]] and his [[War Scribes]].

They never arrived. Once into the Warp, Onyx's Navigators lost sight of the Astronomican at Terra and had to guess their way through the increasingly turbulent Warp. Most of the fleet attempted to drop back to Realspace and tried to make their way back to Imperial outposts. The great exception was the Legion flagship ''Mount Everest''. With Onyx in command, the mighty super-battleship struggled on despite navigational difficulties and a fluctuating Gellar Field. No two members of the ship's complement agree on how long the voyage took or even what exactly happened, but some points are common to their accounts. That the ship itself resisted the touch of Chaos is beyond doubt, if miraculous. However, daemons still boarded the ''Mount Everest'' and the Stone Men fought many battles to save their flagship. At the centre of these battles was Onyx himself. The Primarch's struggle was two-fold: he not only fought against the minions of the Ruinous Powers without, but against the lure of Khorne within. Eventually, the God of Fire and Blood sent his minion Balheizihr the Brazen Bull to claim Onyx's soul or his skull, but Khorne had not reckoned on Onyx's will. Despite his burning flesh and boiling blood, Onyx grappled with Balheizihr until the ''Mount Everest'' broke free into Realspace, then crushed the daemon's skull with a mighty headbutt and banished it back to the Warp.

Once they had control of their ship once more, the ''Mount Everest's'' complement assessed their situation. They were far from their intended destination near the core of the Galaxy. In fact, they had not traveled all that far from Tisenjoch and had arrived at [[Rosskar]] in the Segmentum Pacificus. The ''Mount Everest's'' instruments were functioning poorly but still detected a warfleet attacking Rosskar. Unphased by earlier arguments with Alexandri, Onyx ordered his men to move to the rescue of his brother's homeworld. However, a rescue was already underway. Though Rosskar had been brutally attacked by the genewrought soldiers of [[Pallas Eugenesis]], the fleet in orbit belonged to valiant [[Roman Albrecht]] and was rendering assistance to the remaining defenders. Onyx and Roman met on the [[Steel Marshals]] flagship and, after a friendly embrace and exchange of news, began to plan vengeance on the Traitors. They were quickly joined by the Primarch [[Gaspard Lumey]], who had been mustering his own Loyalist army in the Segmentum Pacificus. In the course of the discussions, Gaspard raised the unpleasant possibility that the Emperor might have been killed in the fighting. Onyx disliked this thought but could not rule it out. Before the Heresy began, Hektor Cincinnatus would have been seen as the heir to the Imperium - but no sane man would follow that Traitor now. Who was the rightful heir? In Onyx's mind, the best choice was the most humble of the Loyalist Primarchs: Roman Albrecht. Reaching his conclusions almost as quickly as Gaspard Lumey posed the question, Onyx turn to Roman and said that he must be Emperor if their father was dead. Gaspard agreed and Roman had no choice but to accept his brothers' decision.

Before the settlement of the Heresy could be concluded, the war must still be won. The three Primarchs agreed to a plan that made best use of their Legions' strengths. Onyx and Roman launched a frontal attack on the Traitor forces guarding the Segmentum Solar while Gaspard's Fifth Legion tried to slip through to Terra. Though the fighting was hard, the Stone Men were slowly reinforced by forces scattered in the failed jump to the Atalantos Worlds and made great progress before the Traitors fled and the journey to Terra was only a procession. Onyx found a sorrowful gathering at the Imperial capital, as victory over Hektor had come at great cost. The Emperor lived - though only barely - and [[Golgothos]] was among the countless dead.