Part I - The Needed Upgrade
Deep within the Golden Tower, far beneath the soaring spires and hallowed halls, a profound industry now hummed. In the Princess's private, subterranean laboratories, a cadre of specially chosen Magos and Archmagos from the Adeptus Mechanicus toiled with tireless zeal and an almost sacred joy. Before them lay marvels unseen in millennia, a nascent era of technological ascendancy about to be unleashed upon the galaxy, each creation bearing Aurelia's unmistakable touch, yet resonating with the ancient wisdom of the Omnissiah.
In the past five months, this secret forge had birthed new creations and initiated the construction of the formidable arsenal for the Indomitus Crusade. Initially, their output had focused on subtle yet impactful upgrades: enhancements for existing weaponry, minor but vital additions to power armour, vehicle modifications, and improvements for close-combat armaments. These were quick, decisive increments designed to give Imperial forces a critical edge in immediate skirmishes and to equip its elite with potent tools against the rising tide of Chaos.
Then, just last month, the production shifted to a larger scale. The Laurel Systems, Aurelia's celestial crown of formed stellar bodies, now thrummed with a furious, coordinated industry. In a few short years, they would be pouring forth such a torrent of matériel—weapons, armour, vehicles, and even battleships—that the Imperium would be overwhelmed, but in the most profoundly beneficial way. The scattered Forge Worlds, too, had been stirred from their millennia of stagnation, subtly guided by Aurelia's influence. They were, without overtly acknowledging it, breathing new purpose into their ancient rites, rekindling the fires of dormant ingenuity that even Mars had forgotten. The Princess, however, harboured no grand ambition beyond this: she simply sought to give humanity a fighting chance in a galaxy that was devouring them piece by piece.
Yet, for Aurelia, even this immense outpouring of matériel was merely the beginning.
She gazed upon her brother, Roboute Guilliman, as he donned his newly upgraded panoply, the venerable Armour of Fate. At first glance, it appeared largely unchanged, its magnificent cobalt blue and burnished gold as iconic as ever. But a closer inspection would reveal subtle nuances: the faint, ethereal shimmer of Noverrium plates seamlessly integrated beneath the traditional ceramite, new optical sensors, and additional hardware that whispered of forbidden advancements. Belisarius Cawl hovered nearby, a chorus of binary hums and quiet clicks escaping his many augmetic mouths, his optical sensors flickering with barely contained pride and profound joy. Aurelia, too, regarded her brother's armour, her celestial eyes alight with a fierce, protective pride.
This was more than just a modified suit for the Primarch. The technologies woven into it were also being integrated into the power armour of his Legion. While not every Ultramarine would immediately receive such advancements—the sheer scale would demand years of production—the captains, Honour Guard, and Chapter Master Marneus Calgar himself, would wear suits of augmented Mark X Noverrium power armour. These were defences worthy of a new age, designed to shield them on the treacherous frontlines of the galaxy.
"Your Primarchal form, Lord Commander," Belisarius Cawl inquired, his voice a dry, metallic rasp. "How does it respond to the integrated augmentations?" Guilliman flexed his gauntleted hand, his mind subtly testing the armour's new parameters. He felt no drastic difference, not truly. It was an abstract sensation, yet undeniably real. He felt lighter, a subtle, almost spiritual buoyancy in his limbs, and more agile than before.
"I have barely registered a discernible change," Guilliman replied, his honesty unwavering. "Yet, a remarkable lightness permeates my every movement. An oddity, but a welcome one."
"A precise feature, Lord Commander," Cawl responded, his satisfaction palpable. "We endeavoured to avoid any interface that would necessitate protracted adaptation. The same philosophy guides the deployment of the Mark X-Noverrium E-X02 Tacticus Power Armour to the Ultramarines. It is designed for maximum familiarity, easing their transition to superior technology."
Belisarius Cawl was no reckless innovator. Every creation, every upgrade, was subjected to rigorous trials and exhaustive validation. And in the Princess's sprawling laboratories, he found an inexhaustible wellspring of possibilities, but also a new discipline. He couldn't implement every conceivable enhancement; Aurelia, with her calm, steady hand, guided his boundless enthusiasm, ensuring that expediency and practicality prevailed over infinite refinement. The Primaris Marines needed reliable, functional equipment first, before further experimental augmentations.
"We must not overextend our reach, brother," Aurelia interjected, her voice resonating with serene confidence and unyielding determination. "It is prudent for them to experience these initial advancements, to acclimate to their new capabilities. Grant us a year, and the legions of humanity will be flooded with superior power armour, with more formidable weapons, and further enhancements. But our immediate focus, until the core needs are met, remains firmly upon survivability." Guilliman nodded, agreeing with her cold logic. Weapons were essential, but a pointless investment if the warriors meant to wield them perished too swiftly.
"As are more advanced vehicles, of course," Cawl added, his metallic chuckle unexpectedly dry.
Guilliman then turned his attention to the Emperor's Sword, the incandescent blade resting beside him. He inspected its length, noting the familiar, holy flames that wreathed its edge, yet also a subtle shift. He tilted his head, his eyes narrowed, scrutinising the fiery aura. A softer, almost tender light seemed to dance within the fierce flames, not battling them, but becoming an intrinsic part of their ethereal weave.
"Has it undergone some modification?" he asked Belisarius Cawl, his tone devoid of accusation, only genuine surprise.
"Archmagos Cawl did not, brother. I did," Aurelia replied, a soft smile touching her lips. "I merely requested his assistance in its transportation for a small… personal addition. I communicated my intention to Father, and he assented."
"Assented to what?" Guilliman inquired, his gaze returning to his sister.
"Within the hilt," Aurelia whispered, her voice gentle, "I wove a single strand of my hair. Now, you shall carry my light always, no matter how far your crusades take you from the Segmentum Solar." As she spoke, Guilliman sensed, upon wielding the blade, a subtle change. The incandescent flames of the Emperor's Sword now trailed a faint, shimmering ribbon of pure, radiant light in their wake.
"Should you kill a daemon with that blade, brother," Aurelia added, her voice now imbued with a formidable, undeniable power, "it shall not merely be banished to the Warp. Its very essence will be annihilated, utterly unmade. And the blade, through my touch, will offer you enhanced protection against the most insidious predations of the Immaterium itself." Guilliman registered the profound leap in the weapon's power. It was no longer merely a devastating blade, but an instrument of utter finality against the Warp's horrors. And, unexpectedly, he felt a strange, comforting presence, a piece of his sister's indomitable spirit, accompanying him into the vast, chaotic unknown.
"And I also integrated Noverrium into the Hand of Dominion, along with other minor, complementary upgrades," Belisarius Cawl interjected, pulling Guilliman's attention back. The Primarch nodded, a deep sense of readiness settling upon him.
"You are now truly prepared, Lord Commander. Fully ready for the Crusade."
"I shall wield these gifts with the utmost precision and purpose," Guilliman replied, reaching for the Hand of Dominion. He allowed a team of attendant Magos to assist him in securing the gauntlet. He knew not what to expect from his sister's mischievous grin. But then, as his armoured fingers flexed, he felt it: a surge of power, not raw energy, but a profound connection flowing through his body, from the gauntlet itself. He felt his armour breathe, its plates subtly shifting and adjusting to his form, to his movements, to his sheer, transhuman strength—without any conscious command from him. It was truly, startlingly alive, a machine-spirit fully awakened, moulding itself to his very being, all his body, all parts. A peculiar sensation, as if the armour were becoming a second skin, sentient and attuned.
"Perhaps, sister," Guilliman coughed, a subtle tremor in his voice, "you might have mentioned this… adaptive quality?"
"And spoil the surprise? Never," Aurelia grinned, her celestial eyes dancing with mirth. "I wished, most specifically, to observe the reaction of the Ultramarines upon their initial engagement."
Guilliman permitted himself a deep sigh, a familiar gesture of an elder brother resigned to his sibling's playful manipulations. His gaze then shifted to a vast, illuminated table laden with a catalogue of new weapons. He had witnessed many of these in the training grounds, watched his Ultramarines test their mettle. They were powerful, intuitively designed, capable of finally penetrating defences that their old armaments had struggled to breach. Arming an entire Space Marine Chapter was a daunting logistical task; arming the vast, sprawling Imperial Army, however, was a challenge on an entirely different magnitude.
"These armaments, I have seen them. They are formidable. What are our current production numbers?" Guilliman asked, his mind already returning to the complex logistics of total war.
"Sufficient to arm the entire Ultramarines Chapter, as well as the defending forces of Terra," Belisarius Cawl confirmed, his servo-skull projecting the meticulously streamlined production figures. "We have prioritised efficient production. In five months' time, we anticipate a throughput sufficient to arm multiple additional Chapters, perhaps even more."
Guilliman's eyes widened, a rare flicker of genuine surprise crossing his features. Barely three months into full-scale production, this output was unprecedented.
"The designs, Lord Commander, are elegantly simple, inherently modular, capable of myriad variations without creating production bottlenecks. Our Forge Worlds and the revived manufactories of the Imperium have never sung with such… joyous efficiency," Belisarius Cawl added, a note of profound pride, even a hint of his characteristic arrogance, in his voice.
"You must place your trust in our production and logistical capabilities, brother," Aurelia interjected, her voice gentle, yet firm, a knowing smile gracing her lips. "You are not the only one capable of such strategic foresight."
"I am profoundly thankful for it," Guilliman replied, his gaze now sweeping across the immense laboratory and creation hub of his sister. At last, he could truly discern the nascent structure that would feed the colossal beast of the Crusade. And what he saw, in the harmonious interplay of his sister's genius and Cawl's relentless industry, filled him with a potent sense of vindication.
Part II – The Lionguard: Her Pride
Before Roboute Guilliman, Lord Commander of the Imperium, departed for the vast, burning expanse of the Indomitus Crusade, he desired a final, profound act of assurance. This declaration took the form of a ceremonial gathering in one of the Golden Tower's immense, sun-drenched yards. Here, arrayed in ranks stretching to the horizon, stood no less than Aurelia's newly founded Space Marine Chapter: the Lionguard. These were the Princess-Regent's personal Adeptus Astartes, a force of Primaris Marines meticulously selected and rigorously trained to embody the very essence of her will. They were to be Her Imperial Highness, Princess of the Imperium of Man, Anathema Solara, and Scion of Terra, made manifest as swords. Her knights, her loyal soldiers, dedicated to eliminating any threat to her life, to fulfilling her every order without question, to going wherever she desired, and to ultimately protecting her existence at all costs—this was their absolute, unquestioning duty.
It was, Guilliman knew, a rhetoric extreme even by Imperial standards, an indulgence of protective instinct that bordered on the fanatical. But the Indomitus Crusade demanded more than mere factories, weapons, and battleships. It required a beacon, a palpable reason to fight beyond grim survival. Guilliman himself, for all his strategic brilliance and unparalleled leadership, understood that the Imperium required more than just his words, his iron logic, and his endless tactical acumen. His sister, Aurelia, was that beacon, that symbol. Though the burgeoning adoration she inspired was neither planned nor desired by either of them, it was a necessary truth. The people, after ten millennia of despair, needed to believe in victory, to truly grasp that humanity had a second chance, that the Imperium could yet rise to something greater. Aurelia embodied that promise, offering a future imbued with hope. She was, in the fragile ecosystem of the 41st Millennium, the most important being in all the Imperium besides the Emperor.
And that was why, next to the Emperor himself, she must be protected. At all costs. Without exception.
Aurelia's gaze swept across the serried ranks of Astartes, her celestial eyes widening slightly in awe. "Brother," she whispered softly, her voice barely audible above the faint breeze, "how many are there?"
Each warrior wore a Mark X-Noverrium S-01 Tacticus Power Armour, a light derivative of the heavier E‑X02 variant, devised as a rapid Mark X upgrade: swift to fabricate, simple to field, and deliberately modular for future advancements. Adorned with pristine gold and white panels and green adorn fabric. Their Chapter badge—a magnificent golden lion's head wreathed in an aureole halo, pierced by a slim, inverted sword—was emblazoned proudly upon their left pauldron. Even though she could not see their faces behind the visored helmets, she felt a profound, almost primal intensity in their collective gaze. Aurelia felt, for a fleeting moment, a trace of exhilaration, even a hint of gentle intimidation.
"In total, eighteen hundred," Guilliman replied, his voice calm, pragmatic. Aurelia turned to him, her eyes wide with shock. "With an additional seven hundred scheduled for activation in the coming cycle. And eight hundred more in addition, for the Luna Base."
"Brother, that is… too many," Aurelia whispered, truly stunned. "The strictures of the Codex Astartes prescribe a limit of one thousand Legionaries. This far exceeds that. I do not think I require this level of personal protection."
"I most strenuously disagree," Guilliman stated, his voice resonating with an uncharacteristic, cold finality. In the recesses of his mind, the horrific spectres of the Heresy replayed in an endless, agonising loop. He had been too late to prevent the betrayal, too late to turn the tide at Isstvan, too late to save Terra, too late to safeguard Sanguinius. He had arrived late to a world strewn with bodies and dashed hopes. And he had found her body, broken, wounded, pierced with holes that should have claimed her life. He remembered the sickening clarity of seeing through her chest, watching her fragile, limping form carried away by anguished Custodes.
Guilliman's face contorted, a raw grimace of pain tearing at his features as these traumatic memories assailed him in unforgiving waves. He closed his eyes, gripping his power-armoured gauntlets tightly, before forcing them open again.
"I cannot fail again. I refused to be late...again. I refused to not be prepared."
"Roboute..."
"I cannot endure that again, Aurelia. I beg of you, sister, grant your brother this small measure of peace. Allow me this ease of mind."
Aurelia's face softened, a profound sorrow twisting her features. She hadn't fully considered the depth of his pain, the agony of his memories. She knew her own suffering, her grief, but it was a sobering reminder that the Heresy had inflicted wounds on every loyal soul. She reached up, standing on her toes to gently touch his cheek, her slender fingers a fleeting comfort against the cold ceramite of his face.
"I am here, brother," Aurelia replied softly, her voice laden with empathy. "I apologise for failing to consider the weight of your own profound grief. It must have been… unimaginably painful. Horrible for you."
Guilliman took her hand, his gauntleted grip firm and warm. Though he could not feel the touch of her bare skin through the thick metal, he felt her presence, unwavering and comforting. "Do not apologise, sister. Memories are for remembrance—the triumphs and the tragedies alike. Thank you for listening."
"I understand, brother," Aurelia affirmed gently. "My own naivety… it is a hard flaw to excise, particularly in this current age. I confess, I sometimes forget that even our Father deemed it necessary to be attended by ten thousand sworn guardians."
"It is that innocence that has shaped your uniqueness, Sister. It is this quality that renders you unique and cherished," Guilliman said and expressed his affection like an older brother as he kissed her forehead, just as he used to when she was a child.
A soft, knowing chuckle escaped her, causing a brief, ghost of a smile to flicker on Guilliman's face. "Then, I shall welcome them. This Chapter shall be my own, and I shall bestow upon them my unwavering trust and my deepest care," she replied.
Aurelia's gaze returned to the imposing ranks of Primaris. "Which gene-seed did Archmagos Cawl employ to forge them?" she inquired.
"That of Lion El'Jonson," Guilliman replied. Aurelia drew a slow, deliberate breath.
"My Lion," she murmured, a tender, melancholic warmth entering her voice. She had adored Lion El'Jonson, his quiet strength and unyielding honour, but knew him to be a man of few words, often socially awkward when removed from the theatre of war and a bit paranoid. Nevertheless, a quiet satisfaction settled within her. Her guardians would be fiercely loyal, implacably protective.
"Indeed, I now understand your wisdom in their selection," Aurelia added with a soft sigh. "And why the small green in their uniforms."
"The sons of Dorn shall stand sentinel over Terra, as is their sacred duty. You will find solace in their impregnable loyalty," Guilliman stated, his gaze fixed on the distance. "And I shall, of course, leave a substantial detachment of Ultramarines within the Segmentum Solar. But you require something more… acutely capable of engaging myriad threats beyond conventional warfare. A sword forged for you. A knightly order for your protection. I could conceive of no more fitting candidate than the sons of the Lion."
"Neither could I," Aurelia conceded, a genuine, unburdened smile finally gracing her lips. "I suppose then, I shall present myself to my new Pride."
With a few graceful steps, Aurelia moved to the edge of the vast yard. The instantaneous sound of thousands of armoured boots clicking together, a synchronised impact, reverberated through the air, an attention so sharp it cut through the din of the Palace.
"Lionguard!" she called, her voice resonating with primordial power, carrying across the vast formation. She felt every one of them lock their attention onto her. "You were not forged for triumphs and banners, but for guardianship. You are my Chapter—my swords drawn, my shields raised, my unseen shadows. Be where I cannot; strike those who would reach for me; watch the doors no foe should find. Stand in the sun when courage must be seen; walk in the dark when silence is the truest armour. My heartbeat is the drum you keep; if it falters, make the galaxy remember why you were made. You are my swords. My guardians. My knights. My Pride. My goldenhearts."
Aurelia's gaze swept over the eighteen hundred visored helmets before her. She saw the captains, the lieutenants, the revered Librarians, and the formidable Chapter Master. She knew they would inherit their Primarch's eccentricities, his quiet intensity, but she welcomed it all. She was, after all, already surrounded by fanatically devoted Battle Sisters, profoundly overprotective Custodes, and an omnipresent flotilla of warships ceaselessly patrolling the system. The Lion's sons would, she concluded, fit perfectly into her complicated, yet fiercely loyal, family.
"My life is now in your hands," Aurelia concluded, her voice soft but absolute. From the disciplined ranks, a single, resonant thud echoed—the sound of countless armoured fists striking breastplates in a unified oath.
"Chapter Master, High Castellan of the Princess, my Champion," Aurelia then announced, a flicker of amusement in her eyes as she presented him to Guilliman, appreciating the sheer eccentricity of the accumulating titles. "Leontus Valeriad."
From the leading rank, a figure stepped forward. He wore a heavy, exceptionally advanced Mark X E‑X02 Power Armour, specifically modified with Noverrium plating. He removed his horned helmet, and Aurelia was momentarily surprised to see a man of remarkably youthful aspect for a Chapter Master, perhaps the physical age of Guilliman. He possessed a stern, stoic face, framed by unkempt, dirty blond hair, his deep hazel eyes betraying a profound intensity.
"My Princess," he whispered, kneeling with a quiet reverence that vibrated with raw emotion.
"You have risen through the ranks, Leontus, demonstrating exceptional leadership, earning the trust of your brothers, and proving worthy of command. You are the first High Castellan of the Lionguard," Aurelia declared, a touch of melancholy in her voice, but also profound satisfaction as she saw in his eyes the same unwavering dedication, the same fierce resolve she had always cherished in her Lion. It made her feel nostalgic, saddened by the past, yet deeply happy for the hope he represented.
A group of Magos and Servitords arrived, carrying a large dark relicary. The Princess waited for them until they were next to her. Then, she unsealed it. Within lay a sword that was not quite light and not quite metal: a long, pale edge caged by a fuller veined in noctilith, its surface alive with phase‑harmonics that sang too high for mortal ears.
"Corona Leonis," she named it softly. "Its field drinks the empyrean and severs it; daemons cut by it do not re‑cohere. Its edge bites necrodermis as if it were parchment. It is a sign of your charge as Chapter Master—and the seal of you as my champion. You will dwell within my inner circle. I will trust you with my life without reservation. Be my gentleman and my protector: grace before violence, and steel when grace must end."
The Princess regarded him intently, as though she anticipated a reaction—hesitation, movement, or any expression of uncertainty. However, she encountered nothing but unwavering devotion and loyalty.
"Do you accept this immense weight?" She added.
Leontus bowed his head even lower, his voice resonating with an unshakeable oath. "My Princess. My Lady. I shall carry it, and more. I swear to the Emperor, and to you, that I shall protect you with my life, until my very last breath. My life is yours to command. Our lives are yours to command. This is my oath. Our oath. The Lionguard's oath."
She leaned and kissed his brow—a private seal of trust, the first and most personal sign that she would stand unarmoured before him—and with it lay upon him the lifelong charge to safeguard her whenever she chose to be thus exposed. "Then take the sword. Rise, my knight. My champion. Rise, my lion."
Leontus rose and, without doubt, took the sword, Corona Leonis. The light of the Princess surrounded him, infusing him with a sense of undeniable purpose. His mind, honed and sharpened, accepted his mission, his oath made manifest.
"For whom do we bare our fangs?" he bellowed, his voice ringing like a clarion call of righteous fury, echoing across the plaza.
"FOR OUR PRINCESS—WE, HER PRIDE!" The unified roar of eighteen hundred Primaris Space Marines shook the very foundations of the Imperial Palace, a thunderous affirmation of absolute loyalty.
The Princess, taking a deep, resolute breath, looked up at the ash-tinged sky of Terra, a quiet conviction settling within her soul. And allowed herself to think that, perhaps, all would indeed be fine.