Alexandra was born to Magnus and one of his fellow scholars on Prospero. She was born early, while Magnus was on one of his scholarly trips to the ruins of other cities. It was a difficult birth, and her mother died soon after. Magnus returned to find his wife dead and his daughter pale and sickly. He used his powers to keep little Alexandra alive but could not fully heal the damage; she would always be thin and weak, tiring easily from any physical exertion. Nevertheless, her mind grew sharp and strong, rivalling her father in brilliance. It came as no shock to anyone that she was warp-touched, and her father was overjoyed. He began training her in the higher mysteries of the warp and she became second only to him in psychic might.
After the Emperors arrival and the founding of the Thousand Sons, Alexandra travelled, often moving between expedition fleets, hunting down knowledge and other psykers to learn from. This meant she was away from the legion when the mutations struck. By the time she arrived back at Prospero, the legion was reduced to a thousand members, but her father had cured them. She remained with her father after this incident, mostly because of an increase in anti-psyker sentiment in the rest of the imperium. She continued her training with her father, and became engaged in a bitter rivalry with the chief librarian, Ahriman, for her father's approval.
During the council of Nikaea, Alexandra spoke with her father against the ban on sorcery, but they were ultimately unsuccessful. She continued training in secret with the rest of the Thousand Sons, and grew even more powerful. Prior to the Heresy, she assisted with her father in attempting to talk to Horus, and later the Emperor. In the battle for Prospero, she had intended to obey her father's commands and not fight, but she let her rivalry with Ahriman get the better of her, and she fought to outdo him in psychic might. She barely survived the battle, for although she was immensely powerful in terms of sorcery, she still had little physical strength, so with her connection to the warp cut by the silent sisters, she was badly wounded and only survived by getting teleported to the Planet of Sorcerers by Magnus, after his fight with the Wolf King.
As her life hung in the balance, mutation once more became rife amongst the Thousand Sons. Ahriman struggled to find a cure, and eventually made several daemon pacts. One of the conditions of the pacts was the soul of one immune to the taint, either Alexandra or Magnus. Ahriman hesitated, knowing how Magnus would feel about him selling his daughter soul, but Ahriman knew she would die soon anyway, so he agreed. After the rubric was cast, and many of the Thousand Sons transformed into mindless suits of armour, the daemons came to take Alexandra's soul.
However, they did not expect her strength and, even in her weakened state, she cast them away. However, she could not hold out against the pull of the warp, and her body died while her spirit became trapped in the immaterium, unable to return. Magnus became angry with Arhiman, both because of his daughters banishment and because of the destruction of the minds of so many in his legion. Before Magnus could strike the killing blow, Tzeentch intervened. Magnus banished Ahriman, telling him to defend himself, for he knew his daughter would seek vengeance.
So it is that, just as Ahriman travels the physical world, seeking things touched by the warp to use in his destined fight against Alexandra, so does she stalk the warp, looking for weapons real enough to use in her future battle against Arhiman. Such is the way of Tzeentch, to raise up one pawn, all the while plotting it's downfall. The only real question is, whose downfall is he plotting, or does it even matter?
I don't own Warhammer or the original pictures and I'm not making a profit from this. If I did own Warhammer I would be a lot richer than I am now and I probably would have moved the plot on a bit. Maybe that'll be my next project...
