Rubric Marines - Origins: The tale of how the Rubric Marines came upon their unique fate is a twisted one. It has its beginnings in the time when the Emperor's primarchs were mysteriously scattered from their incubation upon Terra. The one who would be called Magnus came to rest upon the remote colony world of Prospero.He could hardly have been more fortunate: Magnus was a ruddy-skinned mutant who would have been feared and most probably slaughtered had he arrived on any other world in the Imperium. Instead, he was delivered upon a hidden planet of kindred spirits, because, as fortune would have it, a commune of outcast Human psykers had settled the planet Prospero.Magnus quickly reached maturity, having grown into a giant in the psychic, intellectual and physical senses. He lived in the lone city upon Prospero, which was nestled deep in the planet's ventral mountain range. Tizca, the so-called "City of Light," was a glittering metropolis with silver towers, soaring obelisks and majestic pyramids. Its citizens devoted themselves to the pursuit of knowledge and the mastery of their psychic powers.Magnus too showed great psychic attributes. He did not just channel power from the Immaterium, however, but instead the primarch could see into that very realm. Magnus the Red quickly went from adept to absolute master. And then, one long foreseen arrived upon the isolated world of Prospero in 840.M30. The Emperor had perceived and recognised His prodigy through the Warp and made haste to find him.It was said that the two knew each other immediately -- their minds having long since found each other across the Immaterium. The Emperor immediately granted Magnus the command of the XV Legion of Space Marines -- the Thousand Sons. They had been created from his own genetic profile and thus far had already shown a strong tendency towards psychic mutation.The first thing Magnus did upon taking over the Thousand Sons was to halt the flesh-curse mutation that had swept through the ranks -- although finding the knowledge in the Warp to achieve this cost Magnus an eye. Next, Magnus led the Thousand Sons to join the Great Crusade -- the epic campaign that swept outwards from Terra. It was the Emperor's plan to reclaim Humanity's lost colonies and to establish a galaxy-wide empire.During the far sweeping conflicts, the Thousand Sons made extensive use of their psychic powers. In battle, it was their way to avoid close combat, instead relying upon their sorcerous ways to carry the day. Guile, feints, confusion and misdirection were their hallmarks. The Thousand Sons were very successful, achieving via arcane means what many Space Marine Legions lost vast numbers of their troops to achieve.That the Thousand Sons accomplished their triumphs through deception as often as by strength of arms did not initially draw concern. Victory was victory, after all. However, the further out the Emperor's new realm expanded, the more tenacious grew the opposition. More and more frequently, the Legions of Space Marines would make planetfall and find not colonies of Mankind eager to join the fold of the Imperium, but societies of mutants and psykers who violently opposed them. Many of those they encountered were enthralled to Daemonic forces from the Warp. These new foes were granted powers that few could fail to notice were much akin to those wielded by the Thousand Sons of Magnus.Gradually, it emerged that there were some amongst the Imperial court that were suspicious of the Thousand Sons' methods. Paramount amongst them were Mortarion, primarch of the Death Guard, and Leman Russ, primarch of the Space Wolves. Throughout the fledgling Imperium many called for the purging of all psychic mutations, save the third eye of the Navis Nobilite. The growing schism threatened to undermine the foundations of the nascent Imperium. To solve the growing dilemma, the Emperor Himself convened a meeting on the planet Nikaea to debate. This event would later be known by Imperial scholars as the Council of Nikaea.In the end, neither Magnus nor those who opposed him prevailed, and instead a compromise was adopted. Human psykers were to become a priority -- those that proved they could serve Mankind would be rigorously trained and sanctioned. Outright sorcery -- Daemon-summoning and incantations learned from the entities within the Warp -- was to be outlawed forevermore. To many non-practicers this was a very fine line, for all such powers seem as witchcraft to those who are most suspicious.It was not the decision favoured by Magnus, and the Emperor Himself halted the primarch before he could storm from Nikaea in protest. During that fateful face-to-face confrontation, the Emperor bade Magnus to cease the practice of sorcery and the pursuit of all knowledge related to the arcane arts. It is said that the cyclopean primarch's face appeared as stone as he received his father's command. Magnus bowed, pledging that he and his Legion would obey.