Dînadan:
I recall seeing a few years ago a generator for generating alternate Heresy setups. Don’t recall where though; think it might’ve been by the guys who did the Dornian Heresy (I want to say Bolter&Chainsword maybe?).
I think the crucial thing to make these alternate histories work is figuring out everyone’s motivations for falling/not falling and how Chaos got its hooks into the various primarchs and then building the narrative from there. Consideration should also be given to how close things are to the ‘real’ timeline at the outbreak of the Heresy; for example, if the Emperor and the other primarchs hadn’t treated Lorgar any differently, then him not falling is extremely unlikely as it was the Emperor’s rejection of veneration and Guilliman’s scorn of him that are big motivators in his fall.
Taking that into account how about the following:
Traitors
Arch-Traitor:Roboute Guilliman and the Ultramarines
Outraged by the choice of Horus over him as Warmaster, Guilliman and his Legion returned to Ultramar and focused inwards on fortifying and expanding the Ultramar Empire out on the Eastern Fringe away from prying eyes and oversight from Terra. The Emperor dismissed concerns voiced by Malcador and others, claiming that Guilliman is merely sulking and would come to his senses eventually. Further discussion on the matter was forestalled when the Emperor retreated into his labs to work on the Webway Project.
In an attempt to prove himself more deserving of the title of Warmaster, Guilliman gave his Legion free reign to delve into any means they could find to amass power. Scouring the records of all worlds in the Empire, the Ultramarines noticed common threads over numerous worlds of cults and kingdoms that dabbled with creatures in the Warp. Though dubious at first of the claims that the Warp held power, Guilliman poured over numerous texts, but eventually sanctioned forays into warpcraft.
As the Ultramrines power grew and more and more daemons were bound into servitude by their Librarians and Techmarines, Guilliman drew the attention of the Chaos Gods. Swearing pacts with them, Guilliman declared Ultramar was ceding from the Imperium and cut all communications with it and blockaded all major Warp routes into and out of the Ultramar Empire and signalling the start of the Ultrarian Heresy.
Pawns of Tzeentch: Leman Russ and the Space Wolves
When the verdict of Nikea fell in favour of Magnus and the continuation of the Librarius Project, Russ was furious and the only thing that restrained the two from coming to blows was the threat of the Emperor’s wrath. Russ and his Wolves stormed from the Council and departed with unfettered haste. Raving about the dangers Magnus and his Sons posed, Russ returned to Fenris, calling all his Legion’s Rune Priests to the Fang to decide upon a plan to combat the threat the Crison King posed. The Priests conducted a vast ritual in an attempt to commune with the World Spirit for aid and from the dark a voice whispered in Russ’ ear, confirming the accusations he’d levelled against his brother. Unbeknownst to Russ, the voice was in fact Tzeentch, and the power promised to him came at the price of the souls of his Legion.
Seduced by the Changer of Ways’ lies, Russ and his most devout followers started preparing to strike against Prospero, communing more and more with the spirits in an attempt to stack the Wyrd in their favour. At this time Guilliman had already started his decent into Chaos and he sent emissaries to the Fang to court the favour of the Wolf King. The emissaries spoke of how both brothers had been wronged and how it was in their interest to work together to prove themselves right and urged by Tzeentch in his guise of the World Spirit as to the wisdom of such a move, Russ agreed to the emissaries’ proposal and swore to support his brother.
Playthings of Slaanesh: The Black Legion
The fall of the Luna Wolves was one of the quickest of the Traitor Legions, with very little foreplanning on the part of the Chaos Gods. After Ullanor, Horus threw himself into the role of Warmaster in an attempt to prove himself worthy of the title and, as such, when the Emperor ordered that Magnus was to be recalled to Terra, it fell to Horus to see the orders executed. However, Horus was not told the true reason for Magnus’ recall and as such mustered his Legion fearing that things would come to blows, as had happened in the past with the two unspoken Legions.
Learning of Magnus’ recall from the World Spirit, Leman Russ sent an entire Great Company to Horus’ muster under the guise of aiding his brother while secretly plotting to use the opportunity to dispose of the sysmbol of all he hated. As such, when the Luna Wolves arrived at Prospero, it was with a substantial Space Wolf escort. As Horus prepared to descend to Prospero under a flag of truce to request Magnus willingly turn himself over, the Space Wolf fleet took up position and opened fire on Tizca. Thinking that Horus had turned, the Thousand Sons retaliated, their powers tearing apart the combined fleet. With no other option, Horus ordered his Legion to attack, personally leading the vanguard.
Horus and Magnus met in battle before the Great Pyramid as the combined forces of the Thousand Sons, Spireguard and citizenry of Tizca valiantly tried to fend off the might of the Luna and Space Wolves to little avail. Although Horus was the superior fighter, his martial might paled in comparison to Magnus’ psykery and Magnus was forced to blast his brother asunder. Driven mad by the loss of their primarch, the Luna Wolves pressed the offensive, rampaging through the streets and in the confusion lost the Thousand Sons.
Grief stricken, First Captain Abaddon ordered the withdrawal from the planet and the commencement of a savage orbital bombardment. In the aftermath, Abaddon ordered the Legion repaint their armour black in a sign of mourning and a depression settled over the Legion. Many of the Legion took to self harming and other such masochistic rights as penance and it became common practice to add barbs and spikes to the inside of their armour to cut and tear at them as they fought.
The funk was finally broken when an emessary from Guilliman arrived. He whispered in Abaddon’s ear, pointing the finger at the Emperor, saying it was his fault Horus had died and claimed that had been the real reason they had been sent after Magnus, that the Emperor knew that would happen. Kindled to fury, the Luna Wolves, renamed the Black Legion in honour of their loss, declared for Guilliman when he ceded and vowed to bring eternal pain and suffering to the followers of the Emperor.
Hounds of Khorne: ???
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Grandchildren of Nurgle: Rogal Dorn and the Imperial Fists
As with the Black Legion, the fall of Dorn was quicker than most and in fact did not occur until just before the outbreak of the Heresy. When Guilliman declared he was ceding, Malcador requested that Dorn go to him as the Emperor’s representative, hoping it was a misunderstanding and trusting Dorn’s solidity and levelheadedness to prevent exacerbating the situation.
When Dorn’s fleet entered the Warp, there were widespread blips in the gellar fields, arranged by agents of the Dark Mechanicus. On the long trip to Ultramar, a mysterious disease began to spread throughout the fleet and by the time it reached its destination, half the mortal crew lay dead or dying and even a considerable number of Imperial Fists were close to joining them. Rebuffing Dorn’s calls for talks to sought the matter out, Guilliman offered a cure if only Dorn would join him. Inscenced, Dorn cut communications and ordered the fleet to return to Terra to deliver the news of Guilliman’s betrayal in person and to organise the defences for the attack he knew was coming.
En route to Terra, the fleet was waylayed by Warp Storms and ravaged by the mysterious disease. Before long, all but a handful of non-Astartes were dead, along with all but a seventh of Astartes and of the Astartes left alive, all had contracted it. In despiration, Dorn called out for salvation and was answered. In exchange for the lives of his remaining sons he pledged alliegence to Nurgle and Guilliman’s rebellion.
When the storm abaited, the remnants of the Imperial Fist fleet emerged in orbit over Terra, a shell of what had departed. By this time Guilliman and his allies were in open rebellion and as such none gave it a second thought when Dorn took it upon himself to organise the defence of the Sol System. Under the guise of quarantine, Dorn was able to keep prying eyes away from the Phalanx and his fleet and under the guise of sending ships on errands with important cominiquees he was able to leak plans for the defence to Guilliman.
Remaing Traitors: ???
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Loyalists[/u]
Magnus and the Thousand Sons
When the Thousand Sons were first reunited with their primarch they were being ravaged by the Flesh Change. Magnus bent all his will and learning to solving it, but continuously came up short. When a power within the Warp offered to grant him the power necessary to solve the problem, he almost agreed to the bargain, but relented in a moment of insight and rejected the offer. Turning his back on that solution, Magnus poured a slither of his psychic self into each of his Sons, curing them but burning out his left eye in the process and thus avoided the trap laid down by Tzeentch.
Many years later, after the vindication of the Council of Nikea, Magnus set about expanding the Librarius project and introducing new checks and balances to ensure no psyker crossed the lines laid down by the Council. During a period of rest, Magnus returned to Prospero whereupon he received a vision of Guilliman’s betrayal. Horrified, Magnus called his most trusted captains to a conclave to decide what to do. Not trusting conventional means to get through, Magnus decided to conduct a grand ritual to try and directly communicate with his father. In doing so, he shattered the wards around the Emperor’s Webway Project, allowing daemons to pour into the Palace Basements.
Horrified by what he had done, Magnus recalled his Legion to await his punishment. Angry at what Magnus had done, the Emperor ordered that he was to be brought to Terra for punishment. In reality, although he was angry, the Emperor recognised that the only way to fix things was with the aid of Magnus and his Sons, but being secretive he failed to inform Horus of this.
Ever the good son, Magnus patiently awaited punishment on Prospero and was taken unawares when the traitorous Space Wolf fleet attacked. Thinking Horus had ordered it, Magnus bade his Sons retaliate, indescrimenantly attacking both Space and Luna Wolves. It was with heavy heart that Magnus accepted Horus’ challenge and he wept as he was forced to obliterate him.
The greater part of his strength spent and realising even with Horus dead there was no way to be victorious against the attackers’ onslaught, Magnus instructed Ahriman read from an ensorcelled tome. In a flash of Warp energy, Magnus, the Sons and the remaining Spireguard and civilians of Tizca were whisked away, leaving the Luna and Space Wolves confused.
Long after the Heresy was in full swing and Guilliman’s forces were pressing on towards Terra, the Custodes were fighting a fierce battle in the Webway while the Emperor sat on the Golden Throne. Pressed back to the gateway into the Palace, all was thought lost when abruptly the daemon hordes broke and were driven away. To the astonishment of the Custodes, uncalled and unlooked for the bedraggled survivors of Prospero emerged from the Webway, Magnus at their head. The ritual conducted by Ahriman had teleported them into the Webway and they had spent the intervening time wandering its twisting paths. Magnus abased himself before his father in penance and awaited punishment. A wordless glance passed between father and son and Magnus was horrified to learn the war that now raged and how long he’d been missing for. Without uttering a word, Magnus ascended the Throne, freeing his father up to concentrate on sealing the breach and bade his Legion stand shoulder to shoulder with the Custodes and hold back the daemon horde
Other Loyalists: ???
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