Most of Kain's existence was devoted to seeking out a means of restoring the Pillars, leading to numerous discoveries concerning their origins and purpose. It transpired that they were much more than a human edifice: they had been originally raised by the Ancient vampires, as a weapon of war against the Hylden. The Binding which the Pillars maintained ensured the integrity of the barriers between Nosgoth's Material, Spectral, and Demon Realms. Furthermore, the Elder God lurked in the Subterranean Pillars Chamber beneath their central dais, its tentacles coiled around the nine ancient edifices, and its intentions inscrutable.
However, on their departure, the Hylden cursed the Ancients with immortality, cutting them off from the Wheel of Fate that demanded their souls be returned to their God and re-spun in the wheel. They also cursed them with sterility, ensuring the extinction of the species and the discontinuation of the magic that preserved the Pillars.
The Pillars chose their guardians from birth, and since Vampires were no longer born, new subjects had to be created to sustain the Pillars. Humans were selected by Vampires to be given their dark gift and to serve the Pillars as vampires alongside their masters. The humans eventually rejected the gift and overthrew their superiors, claiming the Pillars for themselves.
However, the Pillars could never be adequately served by the humans, and the magic began to weaken, allowing a particularly powerful Hylden to slip through and set into motion a plan to bring down the Pillars altogether.
The Hylden Lord, projected his soul through the dimensions and possessed the body of Mortanius, the current Guardian of the Pillar of Death. Using this body, he murdered Ariel, the Guardian of Balance. This in turn drove her lover, Nupraptor - Guardian of the Mind - insane, who then infected the rest of the Circle of Nine with his madness. All of this was calculated carefully by the Hylden before-hand.As the Circle descended into madness, the Pillar's magic faltered and the Binding became weaker.
Mortanius, during brief moments of clarity, was able to set in motion a prophecy foretold by the Vampires upon the human rebellion, in which a vampire would one day return the Pillars to the Vampires and thus ensure the binding never fail. He had the nobleman Kain killed and turned into a vampire. Kain was then directed by the ghost of Ariel to murder the remaining Guardians before their madness utterly destroyed Nosgoth. Kain proceeded to do so, and battled Mortanius (it remains unclear whether Kain knew at the time, about Mortanius' possession by Hash'ak'gik). He apparently killed him and Ariel revealed to him the truth of his destiny - that he himself was the final Guardian, the Guardian of Balance, chosen at birth upon Ariel's death to succeed her.
Tainted by Nupraptor's madness, as with the rest of the Circle, Kain rejected the sacrifice and chose to conquer Nosgoth. In that moment, the Binding failed, and the Pillars collapsed. The Hylden were free to enter Nosgoth and begin wiping out all other species.
Some time later, having quashed the Hylden invasion, Kain built the seat of his empire, the Sanctuary of the Clans, around the base of the ruined Pillars in an act of irony, with the central pillar, the Pillar of Balance, as his throne.
As Kain matured, he realised the gravity of his destiny, and the effect of his actions, and dedicated himself to restoring the Pillars by altering the time-stream, specifically using the rogue-element and singular variable of Raziel to do so. He learned of his role as the Scion of Balance, who would return the Pillars to the Vampires, and of his destiny to restore the Pillars altogether. However, the journey to do so would be difficult given the corruption he had inherited from the Circle.
The Pillars represent nine fundamental elements of Nosgoth. Each is served by a Guardian who inherits certain affinities and abilities relating to their given Pillar. For example, Moebius, the human Guardian of Time has the ability to see into and manipulate the time stream.
When viewed facing North, their arrangement from West to East is,
Reaching infinitely into the sky and deep into the earth, the Pillars are a manifestation of the mysterious power that preserves and gives life to the land. The nine ancient Pillars represent the principles of Mind, Dimension, Conflict, Nature, Energy, Time, States, Death, and - at the center, binding them all together - Balance.
The Pillars have stood like silent sentinels over Nosgoth since before the dawn of recorded history, and have perpetually been represented by an oligarchy of sorcerer-guardians known as the Circle of Nine.
Each Guardian is marked from birth, chosen and summoned by the Pillar he is destined to serve for his lifetime. In return, the Guardians are granted longevity and extraordinary powers. The death of a Circle member is inevitably followed by the birth of a successor, whom it is the responsibility of the remaining Guardians to seek out and apprentice into the Circle.
In the decades leading up to Blood Omen, the Circle was infiltrated and Ariel - the Balance Guardian - cruelly murdered. Her assassination, orchestrated by dark forces at work within Nosgoth, sent shockwaves throughout the Circle.
Wracked with grief and tormented by suspicions of treachery, Ariel's beloved Nupraptor - the Guardian of the Mind - descended into madness. In his anguish, he unleashed a telepathic assault upon his fellow Guardians - symbiotically bound, the entire Circle was infected by his madness.
Corrupt and deranged, the remaining sorcerers turned their powers to dark purposes, poisoning the land with their sorcery and abandoning their guardianship of the Pillars, which began to crumble, manifesting the corruption of their patrons.
Kain was born into this decaying world, marked from birth as Ariel's successor, and destined to grow to adulthood ignorant of his intended role as Balance Guardian. He is assassinated, revived as a vampire, and used by the necromancer Mortanius and the ghost of Ariel as the scourge of the Circle. Only once Kain has destroyed the eight tainted Guardians and restored their Pillars is his true destiny revealed - that he is the Balance Guardian, and he too must die for the Pillars to be completely restored.
Kain refused the sacrifice, opting to rule the world in its damnation rather than commit himself to oblivion. His fateful decision triggered the Pillars' collapse; the mighty columns shattered and toppled. Centuries later, Kain established the ruined Pillars as the symbolic (and ironic) seat of his new empire, and set his throne at the base of the unrestored Balance Pillar.
But the Pillars, Kain ultimately realized, are more than just a human edifice - the spiritual and physical health of the land is tied inextricably to the Pillars' well-being. With the Pillars left unrestored, corruption seeped slowly into the land like a poison, turning Kain's empire into an irredeemable wasteland.