Editing Thousand Sons (section)

===Pre-heresy===
The Thousand Sons were one of the late developed legions, being used primarily by the [[Emperor|Big E]] to wipe the floor with whatever remaining resistance there was on Terra during the aftermath of the [[Unification Wars]]. Their creation began during a particularly violent Warp storm which cut Terra off from the rest of the galaxy for a short time. The Crusade ground to a halt for this time period, but the Emperor just shrugged His [[Pauldron|shoulders]] and got to work on other matters. Personally choosing the most genetically stable candidates He could find, the Emperor gathered up as many as met His criteria and implanted them with Magnus's Geneseed. The Legion's creation was extremely slow due to these restrictive criteria, but nobody besides the Emperor knew, aside from genetic stability, what these criteria actually were. After He had successfully implanted 1000 of these individuals, enough to meet the alpha stage of Legion building, He christened them the Thousand Sons. Initially, the Thousand Sons seemed not to be particularly noteworthy in any way; in fact their late creation saw them miss out on the Solar Reclamation completely. They were competent to be sure, but so were all the other Legions, most of whom had developed some particularly outstanding characteristic or other. Additionally, most had by this time a number of nigh-on impossible campaigns to their name, like the IX and XVI Legions, or spectacular exploits of valor and skill at arms, like the XVIII Legion. Yet despite being so apparently mundane, the Thousand Sons were noted to carry, almost to a man, an attitude of smug superiority. They, at least, clearly thought that they were worthy of their auspicious beginnings and special attention from the Emperor. This attitude, combined with them having done nothing to earn it in the eyes of the other Legions, set the stage for the Thousand Sons being rather isolated.

Then, about 20 years into the Crusade, the Thousand Sons began all at once to exhibit psychic powers, finally explaining why the Emperor had spent so much time and effort on them. With these new powers, they became one of the killiest of all the legions, with their powers offsetting their small numbers. It was now apparent why the Legion had received so much personal attention from the Emperor in its creation, and reactions to the revelation that they were all psykers was... mixed. Some thought that making psychic Astartes was a fantastic idea; it just made the killiest weapon in the Imperial arsenal all the more deadly. Most however, did not take this viewpoint. With the Age of Strife having ended within living memory, practically nobody in the Imperium had a particularly tolerant view of psykers. The horrific abominations wrought by mad sorcerers and Warp priests upon Terra and beyond, not to mention all the psychic xenos flitting about, had caused the vast majority of humans to look upon psykers with fear at best, and murderous hysteria at worst. As such, where the Thousand Sons had been regarded with annoyance by other Legions, now they were looked upon with genuine loathing by many of them. The Death Guard and Emperor's Children point blank refused to work with them, and their list of detractors would only grow larger over time. Nevertheless, they were tolerated because they were totally awesome, used their abilities to wondrous effect in service of the Imperium, and in general were exceptionally badass (Superhuman warrior-monk magicians for the win!!). Additionally, despite most in the Imperial Armed Forces hating them due to being psykers, the Emperor never issued any sort of censure of the Thousand Sons. As such, everyone essentially just had to let them be. Their honor roll started to balloon in size and quality, and for a time, they filled a niche of being the guys to call when a psychic enemy needed killing. Even the Emperor Himself utilized them on a number of occasions to combat the horrific psychic xenos known as the [[Khrave]].
[[File:TSHH.jpg|150px|thumb|left|Leave it to the nerdiest of the Primarchs to just self-insert for his legion's colors.]]

As time passed, the Thousand Sons became more and more skilled and powerful with their psychic abilities, but it came with a significant price. They began, in ever increasing numbers, to suffer from an utterly horrific condition known as the Flesh Change. At its most basic, it was an instantaneous mutation into a [[Chaos Spawn|That-Which-Shall-Not-Be-Named]] that seemed to have exceedingly limited predictability in both onset and predisposition. From the very first case onward, even the TSons could see that their use of Warp sorcery was clearly one of the factors that was either causing or exacerbating this problem. However, the TSons arrogantly saw their powers as their indisputable right to wield, and doubled and tripled down on their usage. Needless to say, this put them in a very precarious position. They had initially alienated most of the other Legions by being asshats, and then the realization that they were all psykers had turned that dislike to hatred for many. Now, they were literally turning into half-transformed ''The Thing'' entities at random. If anyone found out about their degeneration, half the Imperium would be calling for their outright extermination, while the other half would look on with tepid support for these calls. As such, they did everything they could to hide the Flesh Change. But the problem would only grow worse over time due both to the Thousand Sons using ever increasing amounts of Warp sorcery, and the near completely random nature of the mutations' onset. So the only way to keep their secret was to just stay away from literally anyone who might report them. Part of this meant that TSons in active war zones would oftentimes just up and leave without explanation (the actual reason being they suspected the Flesh Change coming on but were obviously not going to tell anyone). This just made everyone dislike them even more due to how unreliable they started becoming for no apparent reason.

It was all for naught however, as Malcador's agents, along with the Divisios Telepathica and Biologis, eventually all found out anyway. They all concluded the fairly obvious; the Flesh Change was a series of mutations brought on by a combination of some genetic flaw in the Legion's geneseed combined with their use of Warp sorcery. The bulk of the transformations had occurred while Legionaries had been using their powers, and the usage of Warp energies in general was well known to cause horrific mutations. But rather bizarrely for the most arguably nerdy of all the Legions, no matter how obvious it became that their sorcery was either the root of, or horribly exacerbating, the Flesh Change, the TSons pridefully continued to use their powers. It got so bad that when their Primarch Magnus was found upon Prospero, there were only (ironically) about a thousand of them left. One important thing to note however was that none of the other Astartes Legions seemingly discovered the existence of the Flesh Change, or [[Alpha Legion|if they perhaps did]], they kept it to themselves. So all things considered, the TSons actually did a remarkably good job of hiding their tendency to turn into literal '''NOPE''' at the tip of a hat. The Emperor, who would obviously have known about the Flesh Change since Malcador knew, also never decided to have them destroyed, or even told them to tone down the Warp phuckery just a bit. One would think He might have, given the time and effort it took to make them. But the Emperor was, despite all His genius, bizarrely detached from certain, seemingly important aspects of His Imperium.

Eventually, the Crusade progressed far enough to make planetfall upon Prospero, whereupon Magnus was introduced to his Legion. He was obviously delighted to finally meet his sons but that meeting was sorely tainted by the fact that they basically all had incurable space cancer. Magnus's first priority was obviously to find a way to cure his Legion; if he couldn't he wouldn't ''have'' a Legion much longer. He searched desperately for a way to alleviate the Thousand Sons' problem. He looked through every dataslate the Mechanicum Biologis possessed on psykers, every scroll in Tizca, every xenos tristies on the Warp that he could get his hands on, every scrap of information the Divisio Telepathica could offer. He even pried the brains of Malcador and the Emperor, and still he found no solutions; only infuriating dead ends and paths to nowhere. Of course, just as with the rest of his Legion, it seemingly never occurred to Magnus that maybe constantly channeling the most intensely mutagenic thing in existence through one's body might have had something to do with the problem...

With his Legion quickly running out of time, and no solutions forthcoming, Magnus began to grow truly desperate. Then one day, deep in psychic meditation, he [[Just as Planned|happened upon]] the [[Tzeentch|The Cuttlefish of Cthulhu]] giggling away in the depths of the Warp. As previously mentioned, Magnus apparently made some sort of pact with Tzeentch without truly understanding what Tzeentch was, and certainly not that he had been responsible for the Flesh Change in the first place. It is also not known for sure how or why Magnus thought that dealing with Tzeentch would fix anything, though his reasoning may have been slightly sinister. Or just unfathomably stupid, and [[EPIC FAIL|get used to that bit of irony when it comes to Magnus and his boys]]. It is speculated by some that Magnus ''did'' in fact have some small idea of what Tzeentch was when he dealt with him. Not that he was the practically omnipotent, omniscient god of [[Just as Planned|aetheric dickery]], but that he was a phenomenally powerful, exceedingly dangerous, denizen of the Immaterium. One that, incidentally, Magnus probably knew full well not to screw with. But desperate, out of options, and arrogant as ever, he struck his bargain, and the rest is history. Tzeentch seemingly agreed to whatever pact Magnus had presented or pretended to lose whatever wager he had proposed, and so the Flesh Change would quiet down for a while. Magnus wasted no time thereafter in reorganizing his Legion to his exacting specifications, forming an extremely esoteric system of ranks and divisions of expertise that rivaled even the Dark Angels for sheer inscrutability (though honestly neither system was ''that'' complicated, even if Magnus and the Lion liked to think otherwise). With their Primarch's genetic material having stabilized their geneseed, the Tzeentchian pact having stopped the Flesh Change, and the ease with which the populace of Prospero could be implanted with the TSons geneseed, things started genuinely looking up for the Nerdstartes.

During the next bit of the Crusade, the TSons, now rid of their Warp pimples, started to show their faces in public again. They struck up a friendship with the [[White Scars]] Legion and their Primarch [[Jaghatai Khan]]. Both Legions respected scholarship, and both had a significant number of trained psykers in their Legions who were present even before the Librarius initiative. The primary difference between the two was that the Khan and his sons possessed common sense and restraint, while Magnus and his possessed neither. Despite this difference in how they approached the Warp, their Legions got on swimmingly, and together they would become the backbone of the Librarius project. This project's idea was that, as all the Legions had psychically sensitive Astartes, it made sense to formalize some system of training for them so that they didn't spontaneously explode amongst their battle-brothers. So the Khan, Sanguinius, and particularly Magnus, began exporting some of the training regiments that the psykers of their own Legions used to their brothers. The idea quickly caught on with many of the other Primarchs, though they ran the gambit between loving the idea and thinking it was outright abominable. Some, like Guilliman, thought it was a splendid idea to not only introduce some order to a pretty random element of the Legions (Guilliman loves his order after all), but to render unto the Legions yet another exceedingly useful tool. Others, like Konrad Curze, greeted the idea with total indifference. Still others, chief amongst them Mortarion, hated the idea so much that they refused to allow any Astartes in their Legion to practice Warpcraft. As such, no consensus was ever reached amongst the Primarchs as to whether the Librarius should be adopted wholescale, and so each Legion just did its own thing as per usual. Most did adopt the Librarius structure however.

Though Sanguinius was involved in the initiative's inception, he seemingly had no particularly close relationship with either Magnus or the Khan (though to be fair, a mere acquaintance with Sanguinius had the same level of comradery as close friendship with most other Primarchs). Similarly, the Blood Angels seemed not to have had a close relationship with the TSons, though the two Legions were perfectly cordial towards one another. The Scars would later go on to become the only known Sworn Brothers of the Thousand Sons, and this close bond lasted until the Burning of Prospero. For some completely unknown reason, the TSons and Alpha Legion apparently absolutely hated each other. As in even the Space Wolves were willing to at least ''work'' with the TSons, but the Alpha Legion hated the TSons as much as the Death Guard did, and nobody is quite sure why. Additionally, that animosity was reciprocated just as strongly, again without any public facing reason. One of the theories about this (though unconfirmed) is that the Alpha Legion may have discovered the existence of the Flesh Change, as poking their noses into other people's secrets was their bread and butter. It would make sense as to why the Thousand Sons hated them so much; if word ever got out about ''that'', even the Emperor Himself would have had a hard time keeping the TSons from being straight up annihilated by the other Legions. It would also make sense as to why the Alpha Legion shared the TSons' hatred. Knowing that the TSon next to you might just turn into [[Chaos Spawn|the most horrifying collection of asymmetries known to man]] at random would probably have put even the Night Lords off of working with them. Other than that, the Death Guard as previously noted still hated the TSons, the Emperor's Children still hated them, the Space Wolves would grow to hate them, and everyone else, in the short term at least, seemingly kept their low-level annoyance with them. Magnus was personally known to have been at least somewhat close to Perturabo as well (relatively speaking of course), but no mention is made of their Legions having interacted much.

However, the Thousands Sons' luck ran out eventually. After some decades of Crusading, Magnus and his Legion were called to the [[Council of Nikaea]]: a grand gathering of the Emperor and most of His sons to decide if the Astartes should be allowed to use warp based abilities unsupervised. Magnus attended Council in high spirits, thinking that it was going to be an neutral, scholastic conclave where he would be allowed to extol the virtues of unrestricted psykers. What he didn't count on was that the Thousand Sons, and Magnus in particular, had managed to piss off a ''lot'' of the other Astartes Legions and their Primarchs. Even those Primarchs who supported the Librarius initiative couldn't really defend the Thousand Sons rampant use of Warp powers or Magnus's general attitude. A few of them even sent representatives who were told to support the continuation of the Librarius, but condemn Magnus in particular. Dorn and the Lion were foremost amongst them, though they gave no particular reason as to why. Rather than being an open forum, the whole thing essentially turned into a trial of Magnus and the TSons. One in which they had few friends, but seemingly more than their fair share of enemies.

While Magnus's discovery had been a godsend for the Thousand Sons in most ways, he caused them to develop a number of additional quirks that got under nearly everyone's skin. On top of the Thousand Sons' attitude problems, insular nature and the general loathing of psykers in the Imperium, they had developed an obnoxious habit of completely disregarding the Crusade's military needs if some bit of obscure "lore" caught their attention. Whether it be human, xenos, or otherwise, if the TSons caught so much as a whiff of anything related to the Warp, they would be off to study and collect it. This tendency was entirely down to Magnus himself, as his insatiable curiosity had quickly rubbed off on all the mini-Magnuses that comprised his Legion. It had become such a problem that the Thousand Sons were known to just up and leave active warzones without telling anyone if they found something more interesting to occupy them. Unlike during the days of the Flesh Change, it was not just individual TSons leaving, or small groups. Now ''entire Thousand Sons Expeditionary forces'' would simply vanish without a word if they thought something more worthy of their attention was over the horizon. While this was not recorded to have had any disastrous consequences for the forces involved, one must imagine that anybody who was left holding the proverbial bag would have been royally pissed. They would also completely ignore pleas for aid from other Legions, sometimes for literal ''years'', while they tinkered with whatever [[Blood Ravens|shiny Warp bauble they had most recently happened upon]]. This happened to [[Leman Russ]] on at least one occasion, and was known to have been one of the factors as to why the TSons pissed him off so much.

On top of all that, the TSons had also gotten into at least two serious conflicts with other Legions when they tried to preserve some bit of heretical lore in defiance of Imperial law. An incident upon Ark Reach Secundus saw Magnus and Russ nearly come to blows over a historical repository upon that Magnus wanted to preserve and Russ wanted to destroy. The Space Wolves and Thousand Sons engaged in a small scale skirmish, but the Thousand Sons used non-lethal Warp abilities to disable the small number of Space Wolves who charged them. Sadly however, the Flesh Change decided to pop back up at exactly that time, and one of the TSons turned into an aborted Shoggoth right in front of Leman Russ. Disgusted and horrified, Russ wasted no time in dispatching the former legionnaire. This for some reason pissed off Magnus and the surrounding TSons (which is a little silly as they of all people knew that their former brother was best put out of his misery) and the two Primarchs nearly began brawling. However, Lorgar stepped between them. Lorgar's silver tongue combined with the fact that both Russ and Magnus quite liked him saw the latter two Primarchs stand down. Another such incident involved the Night Lords. Another heretical library had been found by a joint Night Lords/Thousand Sons Crusade force, and the Thousand Sons had so wanted it preserved that they had occupied the building and put up a psychic shield around it. The Night Lords however were under orders to destroy it, as per standard Imperial military policy regarding heretical information. Curze was in overall command of the campaign, and so brought up a massive amount of field artillery to pulverize the structure. The Thousand Sons would not budge however, and began a game of chicken with the Night Lords. The Thousand Sons for whatever reason bet that a group of psychotic mass murdering torturers, decked in skulls and flayed skin, wouldn't blow up a building with TSons still inside. Remember what was previously said about unfathomable stupidity being a pattern? 

At any rate, the two Primarchs had met in person aboard the ''Gloriana-class'' Nightfall to discuss the fate of the library. Magnus plead his case to Curze that the knowledge in the library was not heretical by nature, and that he and the TSons could put it to use for the betterment of humanity. Curze, as one might expect, was completely unsympathetic. After letting Magnus talk for a bit, Curze simply pointed out that he was technically 100% right in his decision to the destroy the library, and that being technically right is the only kind of right that matters when it comes to the law. Magnus tried for a bit of brotherly favor or fraternity, but as one might again expect, Curze wasn't having any of that either. He also tried to argue that, as the self-proclaimed expert on the Warp, he was the one best suited to judge whether or not the library should stand or fall. Curze basically just rolled his eyes, and then ordered the planned artillery strike on the library with the Thousand Sons still inside. The psychic shield held through the first bombardment, but Curze made it absolutely clear that he was more than willing to have the Nightfall completely glass the place if that's what it took. Since he technically didn't have a leg to stand on (he was trying to save an obviously heretical library after all), Magnus very saltily pulled his forces back and Curze leveled the building.

Needless to say, the Thousand Sons had made a lot of unnecessary enemies with their solipsistic douchbaggery, and Magnus ended up having to try to defend all these actions without much in the way of backup at the Council. Sadly for the Thousand Sons, Magnus ended up making a pretty significant ass of himself in front of the Emperor (which is something considering that his primary detractor was ''Mortarion'' of all people). To be fair to the sapient stinkcloud however, Mortarion made a number of quite salient points against the dangers of psychic powers, and Magnus failed in his rebuttal to actually address any of them. The Emperor thus decided that He'd given the Thousand Sons and Magnus far too much leeway in their pursuit of power and knowledge. To keep other Legions from further experimentation, He put the kibosh on the Librarius initiative as a whole, and forbade the use of psychic powers in Astartes combat. However, He did not issue any formal sanctions against anyone at the Council, as He essentially admitted that His directives had been implicit. He'd been relying on the individual Astartes Legions to act with an abundance of caution that the Thousand Sons and Magnus simply did not have. Had Jaghatai Khan, with his common sense and mustache, represented the psyker cause at the Council, there's a good chance things would have been different. Alas, he was so far afield that by the time word of the Council's decision on the Librarius even reached him, the Heresy had already started.

The Thousand Sons were forced to dissolve their Librarius along with everyone else, except for the White Scars, who ignored it, the World Eaters, whose Librarium was so small they didn't even bother disbanding it, the Space Wolves who believed that their [[Rune Priest|librarians]] somehow weren't working with the warp (and who the Emperor made an exception for), and the Word Bearers, who were already [[Heresy|quietly sacrificing people to chaos]]. Obviously, this had a far larger impact on the Thousand Sons than on any other Legion. Psychic powers had essentially formed the core of the Legion's combat doctrine and character, and they were sorely missed in the next few of their campaigns. Predictably however, Magnus didn't give a shit either and headed home to Prospero to continue being a sorcerer in secret. The Thousand Sons in general actually did go along with the ban for a short time, but quickly realized that, as long as they stopped being so flashy with their powers, there wasn't really anyone around to tattle on them. As such, they quickly started back up again, and simply avoided using their powers around anyone who might tell the Emperor. There would be rumors sure, but the Thousand Sons figured that there would be rumors even if they actually did hold to the ban.