Magnus the Red

Sexy bastard...

Magnus the Red is the primarch of the Thousand Sons, and rules over the planet of the sorcerers. He was sort of a badass once. He is notable for having a big ol' red eye right in the middle of his forehead, red skin and being hueg liek exbawks, even as far as SPESS MEHREENS go. Depending on who you ask, he may also be the Primarch of the Blood Ravens, which would explain both their color scheme, high percentage of psykers, and Hair-esy.

The Great Crusade

Magnus landed on the planet of Prospero (A planet who's ancient civilization was composed predominantly of psykers, who had fled there because, by and large, Psykers were persecuted by humanity writ large). As Magnus was himself a Psyker, he formed a kinship with the people of Prospero in short order. Taken in by Prospero's people, Magnus absorbed knowledge like a sponge, and became a powerful, and in time, far exceeded the power and control of all his teachers. In time, he had become the single most powerful thing on the fucking planet, and he led a campaign to eradicate a race of predators on Prospero known as the Psychneuein, which overran many of Prospero's early cities and had a fondness for laying their eggs in unsuspecting psykers' brains. The beasts had destroyed the entire population of Prospero, save for its capital city, Tizca. One by one, bit by bit, Magnus' forces retook the planet, putting the Psychneuein to the sword, and within a year, Magnus had completely reclaimed the entire world.

Once the Psychneuein were destroyed, Magnus became the planetary leader by popular demand. Magnus decided to be fucking awesome, and he rebuilt the cities. Like a somehow-perfectly stable fortress some 50 years in in Dwarf Fortress, Tizca became arguably the most beautiful in Imperial space, with crystalline spires and pyramids, long marble roads, and psychically-resonant crystals in key locations, designed to calm the turbulent minds of younger psykers and help them control their burgeoning psionic potential easier. The city quickly became known as a shining jewel of humanity, and one that showed proudly how far its citizens had come from the brink of near-extinction.

All this time, Magnus continued to codify and research everything he could about the Great Ocean - what the Prosperans called the Warp. Huge central libraries filled with knowledge about psychic powers and about the warp were established, and Magnus himself used his powers to ply the very warp itself, claiming many of its secrets, though at terrible risk to himself. Whilst this was exceptionally dangerous, much of what the Imperium's Inquisition currently knows about the warp itself came directly from several of his manuscripts that survived.

With such a powerful mind heading into the warp, it was inevitable that the Emprah would eventually take notice. So he finally came to Prospero, and he and Magnus psychically brofisted before talking for several days. The Emperor taught him even nore about psychic powers, but cautioned Magnus to not over-do things, since foul horrors lurked in the warp and liked nothing better than forcibly sodomizing an unprepared Psyker's soul. Magnus took much of this to heart - but what the Emperor did not know was why - Magnus' forays into the warp had already came at a price - his right eye, lost to mutation when he had consorted with warp-entities whose nature he did not understand until the Emperor explained shit.

Magnus was put in charge of the Thousand Sons, but would not immediately embark on the Great Crusade - so much of his chapter were psykers, and there had been so many small mutations that a number of them couldn't survive the gene-seeding process. Magnus had been aware of the mutations his people were suffering, and he had entered the warp previously to gain answers as to the cause and cure - though Mangus didn't know it, he had consorted with Tzeentch right before he arrived, and the god of Just as planned saw a lot of potential in this one.

In any case, because of the setbacks that had befallen the Thousand Sons, the selfless efforts of Magnus to save them, their shared psychic talents, and the continuing suspicion of many in the Imperium and among the other Space Marine Legions towards the Thousand Sons' use of psychic abilities and the rampant mutations present in their gene-seed, the Primarch and his Astartes developed an extremely close emotional and psychic bond - arguably the strongest such bond among all Primarchs and their Space Marine Legions, exceeding even the Luna Wolves' dedication to Horus.

Finally, about half-way into the Great Crusade, 100 Terran years after it had begun, the now "stable" and full-strength Thousand Sons Legion, with Magnus leading them into the field, were permitted to take part in the effort, as the 28th Expeditionary Fleet of the Great Crusade. And it was glorious. When they were called to the field, the Sons were a sight to behold, flinging forth psychic storms to consume enemies of the Emperor and striking with both precision and prescience, using their abilities to ascertain enemies' weak-points. Magnus was unique among the Primarchs in that he would always try diplomatic routes first, however - in this way, the Thousand Sons won many battles without so much as a shot fired. This did not sit well with Rogal Dorn or Guilliman, who viewed this as unmanly. Likewise, Magnus drew constant distrust from Mortarion and Leman Russ, who distrusted the Sons' sorcerous ways and were somewhat concerned by a trait the Sons had picked up: after conquering or annexing a world, they would take huge amounts of knowledge - books, scrolls with forgotten lore, and ancient artefacts - back to Prospero for study, analysis, and codification.

It wasn't long before Magnus was called to task by his brothers. The Sons' obsession with preserving valuable knowledge - whatever the source - pissed off several of the other Primarchs. The Thousand Sons' political opponents among the other Astartes Legions found useless, and arguably counter-productive to the goals of the Great Crusade which sought to spread the specifically Imperial strain of human civilization across the galaxy, and possibly dangerous to boot, since the Warp was do dangerous. Arguments between Magnus and the other Primarchs became so pitched and so violent that on one occasion, Leman Russ and Magnus got into a giant fucking brawl on the council floor, and it only didn't end in bloodshed because Lorgar managed to talk both of them down, causing Russ to grudgingly holster his weapon and Magnus to stop chargin' his lazar. Finally the Emperor stepped in, bitch-slapped everyone for acting like a retard, and pointed out that whilst dangerous, Psychic powers were extremely necessary to the Imperium writ large. Chaplains were added to Space Marine chapters in order to ensure adherence to the Imperial creed, and Psykers were to be properly sanctioned by the Imperium. Magnus was ticked off, but calmed down a bit a little later and continued the Crusade with the new restrictions in place.

When Magnus learned that Horus intended to betray the Emperor and slaughter the other Astartes Legions, he sought any way possible to warn the Emperor. With no other option, he used his sorcerous powers to open an Eldar Webway portal and used it to travel within range of the Emperor. Unfortunately, his doing so destroyed a top-secret Webway project that the Emperor had been working on for months, which would have rendered dangerous warp-travel obsolete and would connect the Imperium of man using a human-engineered version of the Eldarin webway gates. He called Magnus to task for using Sorcery to activate the webway on top of this, refused to listen to Magnus about Horus, and declared Magnus a DOUBLE HERETIC. Magnus fled the scene rather than fight with his own father, realizing that the Imperium was comprehensively fucked and that he needed to do all he could to protect it and Prospero.

When Horus learned of Magnus' attempt, he was quietly amused. The Emperor ordered Horus to have Russ bring Magnus back to Terra to stand trial for what he had done, and Horus, being a dick, quietly altered Russ' orders to lay waste to Prospero and slaughter the Thousand Sons. As Magnus was already a declared double heretic and he hated Magnus even before this, Russ took to this like a Furry to Ironclaw. Accompanying the Space Wolves were a full contingent of Adeptus Custodes, millions of Imperial Army troops, and the elite Imperial anti-psyker unit, the Sisters of Silence (think a unit full of Culexus Assassins and you get the general idea).

Magnus, sensing this, and realizing that this had been Just as planned and that Tzeentch had done this intending to completely destroy both the Thousand Sons and the Space Wolves decided to dick with the Lord of all Fate: He decided to accept the destruction of everything that he had worked for, so that Tzeentch's ultimate goal would only be half-fulfilled. Tzeentch was richly amused by this. As Prospero burned, Tzeentch and Magnus engaged in act after act of dickery and counter-dickery, with Magnus finally pushed into a towering rage and taking to the battlefield at his capital, crushing his enemies with volleys of MIND BULLETS before he engaged Leman Russ in close-combat. The two fought fiercely, when Magnus managed to Falcon punch Russ so hard it shattered his breastplate and punctured one of his hearts. Russ was still in the battle, though, and after poking Magnus in his single eye, performed a back breaker on him and ended the fight. Tzeentch was greatly amused by all how this panned out - it's rare that anyone, let alone a mortal man, could try to out-manipulate the architect of fate himself. He thus made Magnus an offer: Become Tzeentch's servant, and perserve what was left of his legion and homeworld, or watch what was left of both burn as he lay dying.

...For Magnus, it never really was a choice. The response of Magnus' new patron was immediate - for once, Tzeentch was true to his word. The City of Light was transported into the Eye of Terror to a new Daemon World. Prospero was destroyed that day, but Magnus and his Legion survived. By the time the Thousand Sons were seen next, they had joined up with Horus' force of Traitor Legions on their way to lay siege to Terra, and Magnus the Red had become the most powerful of all Tzeentch's daemonic servants. Magnus had never served Tzeentch willingly, but now had no choice - exactly as Tzeentch had planned from the very beginning.

He doesn't get much press-time because of how bad he and his Legion got dicked by Tzeentch - but when he gives enough of a shit to get up and join the fray, you watch your ass.

The Primarchs of the Space Marine Legions
Loyalist Corvus Corax - Ferrus Manus - Jaghatai Khan Leman Russ - Lion El'Jonson - Roboute Guilliman Rogal Dorn - Sanguinius - Vulkan
Traitor Alpharius/Omegon - Angron - Fulgrim Horus - Konrad Curze/Night Haunter - Lorgar Magnus the Red - Mortarion - Perturabo