With the embracement of chaos, comes mutation. Members of the legion began suffering horrendous changes and having their bodies and minds twisted in ways only chaos can achieve. Although some saw these changes as a sign of their god’s favor, those of higher understanding knew better, and decided that their search for enlightenment and knowledge could not end in the dreaded transformations they would inevitably suffer. (Magnus, however, was already a very powerful daemon prince) Ahriman, Chief Librarian of the Legion, and second only to Magnus in power, united a conclave of his most trusted sorcerers, and together they cast a spell, currently known as the [[Rubric of Ahriman]], of tremendous magnitude that would save the legion from the fate of mutation. The results were not what Ahriman wanted, much less expected. The Thousand Sons were now safe from the taint of chaos, but at a terrible price. Those who had psychic powers were greatly strengthened. But those who hadn’t had their physical bodies reduced to dust and their souls were damned to live inside their armors forever, changing most of the legion into little more than mindless ghosts. When Magnus heard about the terrible failure, he banished Ahriman and his group from the Planet of the Sorcerers, and now they wander errantly through the [[the Eye of terror]], still pursuing magical knowledge and seeking arcane artifacts. Ahriman’s current goal is to enter the Black Library of the Eldar, and rumor has it that if he succeeded in his quest, his power would grow beyond imagination.