From Epochs of Askellon;
The time of peace {following compliance} was brief, as soon civil war on a scale undreamt of erupted. Many tales speak of how the sector’s people fought valiantly during the dark times when the Imperium was nearly split asunder during the Horus Heresy. Though much of the region faced horrific damage and many of its main worlds were reduced to ruin, Askellon, like the Imperium, survived.
Almost unnoticed amongst these early days of unification and rebellion were the first recordings of terrible Warp storms raging across the once-peaceful region. Twisted legends began that the storms were growing in appetite, and only abated after they had devoured sufficient ships or worlds to sate themselves temporarily. It was not until millennia later that Argo Kappellax, then Arch-Magos of Cerix Magnus, established they were not legion but instead a singular storm, rising and falling, though no aerythmatical formulae could fully predict its actions. The name the Navigator Houses of Askellon cursed it with ages ago, Pandaemonium, soon became commonplace amongst those who ply the Warp routes across the sector and beyond.
The Infernal Storm continues to ravage the sector to this day, with periods of relative calm only to be followed with times so tumultuous that interstellar travel and communication become nigh impossible. With each generation it appears to grow stronger, though most assume this is more a reflection of Askellon’s earlier, more golden ages than any true measurements. Some scholars believe that the Pandaemonium is once again growing in fury, this time to a level that reality itself might not withstand the storm surge....
For several millennia, Navigators and Chartist Captains have considered the region, ever traitorous and poorly charted, as ill-aspected and in some manner cursed. Instances of vessels cast violently off course, barely surviving passage or vanishing entirely, are growing. Already, numerous charts state simply “Access Denied,” where before they listed the details of the cursed sector, a warning that some who enter it might never return. Though it is a period of seeming calm, it grows in rage and hunger, but for what none dare say. Its power is limited not only to Warp travel; entire planets have been engulfed or lost behind its storm front, becoming isolated for generations. Doomsayers cry that the storm is drawn towards those worlds with the greatest populations of Psykers, or worse might be itself causing the increasing number of these and other Mutants. Heretical texts claim it is a manifestation of ancient sins revisited on the living, or the spirit of betrayed souls screaming for vengeance, and is so deeply entrenched within the stones of the sector’s fortresses and the souls of its people that it may never be excised. Though none would openly countenance such beliefs, few Askellians disagree that it holds the sector in a vice that is ever closing.