The Dark Dimension was, in essence, a barren and desolate subspace, existing in a form beyond human perception. That was until Dormammu discovered it...
At that time, he did not yet bear that name; he was merely an obscure sorcerer from ancient times.
The era in which Dormammu lived was a savage age where magic was in decline. Sorcerers were regarded as evil heretics, servants of the devil, unrecognized by the Church. Worse still, they were misunderstood and despised by the world, accused of desecrating the corpses of the dead, manipulating terrifying spirits, and branded as unforgivable blasphemers!
Thus, the Middle Ages saw the rise of the frenzied witch trials and the witch hunts, a malignant tide that swept across Europe and persisted for nearly three hundred years. That was a dark chapter in the history of human civilization.
It was not until later, when the sorcerer Agamotto emerged, inheriting the ancient sanctuary of Kamar-Taj, communing alone with the trinity of the Vishanti, and establishing an equal covenant with them, that a complete system of sorcery was formed, allowing the legacy of magic to endure.
Had Dormammu been born in that era, he might not have become the Dark Lord he is today. But fate is a curious thing. As an obscure sorcerer, Dormammu was unwelcome in his time.
Then, one day, while attempting to commune with the deities he worshipped, he stumbled upon the existence of the Dark Dimension by chance.
As a practitioner of dark magic and a necromancer, Dormammu did not hesitate or struggle with his decision. He made the critical choice to abandon his human form, entering the Dark Dimension as a soul. Through the continuous absorption of power, he gradually grew incomparably strong.
Over the long passage of time, Dormammu forgot his human name. After merging with the Dark Dimension, the dark energies slowly assimilated his will. This ruler embarked on an evil journey to conquer countless dimensions.
By then, Agamotto had already become the supreme leader of sorcerers, establishing the Three Sanctums and erecting an impregnable defense for Earth.
Unsurprisingly, Dormammu was barred from Earth, despite his fervent desire for this planet, which was rumored to be the heart of a cosmic deity.
As the ruler of the Dark Dimension, he was regarded as an outsider by the material world and thus denied entry.
And so, a fierce struggle spanning a thousand years began. Dormammu ceaselessly drove his zealots (fanatics corrupted by the dark energies) to dismantle the Three Sanctums and destroy the material world's defenses.
Meanwhile, Kamar-Taj remained vigilant, with the Ancient One regarding this ruler of the Dark Dimension as her greatest enemy.
Until today!
After a thousand years, Dormammu was finally about to reap the fruits of his success. Kaecilius had completed his mission flawlessly. The Three Sanctums had crumbled, the material world's defenses had collapsed, and the Six Lords of Hell had led legions of infernal creatures in a full-scale invasion of Earth, suddenly turning their fury upon the Ancient One.
Thus, from the very beginning, Dormammu believed victory was assured. He only needed to wait and savor the Ancient One's expression of agonizing despair.
With such an overwhelming advantage, how could he possibly lose?
"Ancient One! Human! The Dark Dimension… I am its sole ruler!" A cold and furious will reverberated like a boulder crashing into a still lake, sending violent ripples across its surface.
Dormammu's spectral head suddenly ignited with terrifying and wrathful black flames. Countless decaying planetary remnants trembled violently, as if caught in a tempest, crumbling to dust in an instant.
"Not anymore." Sean said calmly, resisting Dormammu's psychic assaults while continuously channeling the power of the Mind Stone to sustain the Ancient One.
After all, Dormammu's roots ran deep. Having long been entrenched in the Dark Dimension, he had become one with it, inseparable. Seizing control from him was no easy feat.
Were it not for the Ancient One's prior absorption of the Dark Dimension's energies which granted her profound understanding of the mysteries between soul and dimension, and the overwhelming power of the Mind Stone, this once-in-a-millennium opportunity would never have arisen.
Otherwise, breaking this deadlock would have been far from simple.
"So this is what it feels like to abandon the mortal body and exist as pure soul." The Ancient One, now manifesting as a colossal figure, steadily eroded the Dark Dimension, absorbing its vast energies.
Meanwhile, Dormammu frantically drew upon the boundless dark forces, struggling to resist or halt this process.
The ruler of the Dark Dimension could not suppress a rising sense of panic. He felt himself weakening... slowly, almost imperceptibly, yet relentlessly.
It was like slitting one's wrist and watching the blood seep out, step by step, into the abyss of death.
"You thieving wretch!" Dormammu's enormous eyes fixed upon the Ancient One's towering form, his rage so intense he could barely restrain himself from cursing outright.
This was an exceedingly rare occurrence for one who had long forgotten human emotions...
The Ancient One, her physical form already destroyed, merely smiled gently, offering no rebuttal.
Bathed in radiant white light, encircled by divine halos, she appeared almost godlike. In terms of sheer presence alone, the Ancient One already outshone Dormammu by a wide margin.
"He really should have worked on his image more." Sean mused to himself.
Time did not flow within the Dark Dimension. This utterly stagnant and silent realm was the eternal paradise Kaecilius had so fervently yearned for, a place where one could escape the cage of time and the inevitability of death.
But it was nothing more than an illusory dream. All things in existence must meet their end. This was the immutable law of the universe.
"Ancient One! What of your faith in Kamar-Taj?"
At first, Dormammu sought to shatter the Ancient One's psychic projection, stirring the entire Dark Dimension in an attempt to annihilate and corrupt her soul.
But he had underestimated her will. Having cast aside her mortal shell, the Ancient One had ignited an indomitable spiritual flame. Her mind, refined and unyielding, was utterly impervious to Dormammu's petty tricks.
Later, the Dark Dimension's ruler tried every tactic at his disposal, even resorting to desperate pleas, offering to relinquish his ambitions toward Earth.
Yet the Ancient One remained unmoved, and Sean paid him no heed. The two were like brazen thieves who had stormed into Dormammu's domain, plundering his wealth without restraint.
Before discovering the Dark Dimension, Dormammu had been a nobody, a nameless sorcerer. Compared to the Ancient One, who was born of noble legacy and possessed unparalleled talent, the gap between them had been insurmountable.
Now, stripped of the Dark Dimension's support, the Ancient One pressed forward relentlessly, while Dormammu found himself struggling, unable to hold his ground.
"You heretic! Treacherous betrayer! As a sorcerer of Kamar-Taj, you forsook the faith of the Vishanti and embraced the Dark Dimension! How are you any different from Kaecilius?!"
Dormammu roared in fury. As the sole sovereign of the Dark Dimension, he had never imagined that anyone would dare attempt to steal his power.
This was the flaw of rising too swiftly...
Seated upon the Dark Dimension's supreme throne, Dormammu had taken it for granted that no force could threaten him. He never anticipated the day he would be toppled from his rule.
Now, the Dark Dimension no longer belonged to him alone.
"Our struggle will span millennia. In time, one of us will inevitably become the other's sustenance." The Ancient One's thoughts rippled faintly, yet her words were ice-cold.
Empowered by the Mind Stone, she no longer needed a mortal vessel. She had willingly merged with the Dark Dimension, choosing this path to shoulder her heavy burden.
"Tell Strange he will be the next Sorcerer Supreme." said the luminous figure bathed in white light, smiling faintly at Sean.
Then, with a flicker of energy, the Eye of Agamotto materialized before him.
"In the end, you became the victor, Sean Cyphers." The Ancient One said softly, "May you not be the one who heralds the doom in that unpredictable future."
Sean reached out and grasped the Eye of Agamotto. Its golden casing, engraved with intricate patterns, encased an emerald-green gemstone resembling a pupil.
As the bearer of three Infinity Stones, he could sense the immense power contained within the Eye of Agamotto; the secret of time itself...