High School DxD: The Lucifer's Devil Trigger — Chapter 29

Chapter 29: The Knight’s Oath and the Empty Castle

To be completely honest, Kuroka hadn’t known what to make of the woman at first.

A Devil and a Holy Sword Wielder. The combination felt inherently contradictory, like mixing oil and holy water. Back then, Kuroka couldn’t fathom why Levi believed someone like Artoria could ever truly assimilate into their ranks, let alone willingly reincarnate as a creature of the Underworld.

But as the days bled into weeks, the barrier between them naturally dissolved. It was simply impossible to dislike her.

Despite bearing the title of King Arthur and wielding a legendary Holy Sword, Artoria’s stance on Devils lacked the fanatical rigidity of the Church. After signing a temporary contract with Levi, she never once looked at them as though they were alien monsters or walking sins. As long as a situation didn’t violate her core moral bottom line, Artoria was remarkably adaptable. Give her a clear explanation of the cause and effect, and she would simply nod and draw her blade.

Whenever a fight broke out, she was always the first to charge into the fray. Even surrounded by Devils, her knightly instincts took over, placing herself at the vanguard to shield them from harm.

Why did they consider her one of their own?

The answer was obvious. It was because she had treated them as her own people first.

“Lord Levi,” Kuroka asked, her golden eyes shifting toward the man beside her. “If Artoria really wants to go and see for herself, how do you plan to handle it?”

Levi leaned back against the plush fabric of the sofa, crossing his arms. A faint, knowing smile played on his lips. “Do I look that short-sighted? I’ve already made up my mind. But if she truly intends to walk that path, we need to prepare the board in advance.”

He shifted his gaze to Grayfia, who had just returned to the room after departing before dawn. “I’ve already asked Grayfia to arrange the specific items, though it will take a little time. Honestly, I have a fairly accurate read on what she will choose.” He offered the silver-haired maid a warm nod. “Thank you for your hard work, Grayfia. There have been far too many moving pieces lately. If it weren’t for you, managing all of this alone would be a headache.”

“It is nothing major,” Grayfia replied, her posture immaculate, her tone perfectly measured. “As your Queen, it is only natural for me to shoulder a portion of your burdens.”

“You’re truly reliable.”

As Levi and Grayfia fell into a casual rhythm of conversation, Kuroka sat opposite them, her twin tails swaying in a slow, thoughtful tempo.

A little further away, Ingvild watched the exchange, her gaze flickering between Levi and Grayfia. A quiet, heavy resolve settled over her features. Unlike Sakura, who had only recently reincarnated from a human, or the young Shirone, both Kuroka and Ingvild possessed a crystal-clear understanding of the current power dynamics within their peerage.

Kuroka was a rare genius among the Nekomata. Having survived the grueling artificial extraordinary experiments, her physical and magical limits had been shattered. Her strength had been rising at a terrifying pace, long since breaking into the world of an Ultimate-Class Devil. The only thing keeping her from the next tier was the sheer volume of her magic power. Once her reserves deepened enough, stepping into the Satan-class was a guaranteed certainty. She possessed the raw potential to eventually stand at Grayfia’s height. With enough time and the right catalysts, even reaching the extraordinary domain wasn’t entirely out of the question.

Of course, such opportunities didn’t just fall from the sky. Even Grayfia herself was currently bottlenecked at her current peak.

Ingvild, on the other hand, was an entirely different anomaly. Her current magic power reserves were already comfortably sitting at the Satan-class. According to Grayfia’s careful assessments, the sheer density and quality of Ingvild’s demonic energy surpassed the average Satan-class Devil by a wide margin. Merging with the latent power of the original Satan Leviathan had been like pouring an ocean into the perfect vessel.

When Ingvild had first awakened, groggy and unacclimated, she already passively emitted the pressure of an Ultimate-Class Devil. Coincidentally, that had been the absolute upper limit of what Levi could safely convert at the time. A mere week later, once her body fully adapted, she effortlessly crossed the threshold into the Satan-class.

Prior to her awakening, she had known absolutely nothing about the supernatural world. Grayfia had taken her under her wing, personally guiding her through the complex mechanics of her Sacred Gear, resulting in a meteoric spike in combat effectiveness.

Now, the two girls stood on diverging paths of progression. Kuroka simply needed to accumulate raw power to naturally ascend, while Ingvild possessed boundless power but needed to master its application to grow stronger.

Grayfia, Kuroka, and Ingvild. These three represented the absolute pinnacle of potential within Levi’s forces. Sooner or later, their names would echo across the supernatural world. By comparison, Sakura and Shirone were still in their developmental infancy.

Watching Grayfia smoothly manage Levi’s affairs sparked a quiet fire in both Kuroka and Ingvild. They bottled up their frustration, silently vowing to push themselves harder. The day they could stand as Levi’s true swords and shields was approaching; they just needed to bridge that final gap.

Their silent calculations were interrupted by the soft, rhythmic sound of footsteps on the stairs.

Artoria descended into the room. As if pulled by an invisible gravity, every pair of eyes turned toward her. Then, driven by a collective, unspoken respect, the group naturally parted, giving her space to breathe.

Taking in the sight of the people gathered in the room, the corners of Artoria’s mouth curled upward.

If someone had told her upon her arrival that she had fallen straight into a demon’s den, she might have agreed. But now, looking at the faces looking back at her, she felt a deep sense of warmth. She had always been blessed with extraordinary companions. Her knights, her friends, and now, this strange, makeshift family.

She took a breath, her posture straightening into the regal bearing of a king.

“Levi. Everyone,” Artoria spoke, her voice clear and unwavering. “I have made up my mind.”

The room fell dead silent.

“Perhaps this decision will subject me to suffering for a time, and it will likely cause trouble for all of you. But if the opportunity exists, I still want to see it for myself. I need to witness the culmination of my choices, my decisions, and the path I have bled for all these years. I need to know what it truly amounts to.”

Levi met her gaze, his expression completely devoid of surprise. “Won’t you regret it?”

“Perhaps.” Artoria offered a gentle, self-deprecating smile. “But there are certain things in this world that you must face, even knowing they will bring you regret and sorrow. Because only by walking through that regret and enduring that sorrow can you ever hope to welcome a true tomorrow.”

Levi studied her face for a long moment. Finding not a single trace of hesitation in her emerald eyes, he withdrew his gaze.

Reaching into the void of his system space, he retrieved a small, ornate box. He flicked the lid open, revealing two obsidian chess pieces resting on velvet. He picked them up, the twin Knight pieces resting heavy in his palm.

“Alright. I understand your resolve,” Levi said, his voice dropping an octave. “I will help you see this through. So, let us forge a new contract.”

Artoria knew exactly what the Evil Pieces represented. She stared at the two Knights in Levi’s hand, fully aware that a single nod would strip away her humanity, binding her to the Underworld as a Devil for the rest of her existence.

Once upon a time, her pride as a knight of humanity would have violently rejected the very concept.

But now, she didn’t hesitate for a fraction of a second. She nodded, stepping forward and reaching out to accept the pieces.

The moment her fingers brushed the obsidian, the pieces fractured into crimson light, melting into her chest like shattered sunlight. A violent, alien power detonated within her veins, flooding her limbs and bones. The temperature in the room spiked as an intense, searing heat concentrated on her shoulder blades.

With a sharp tearing sound, a pair of majestic, jet-black wings violently burst from the back of the Holy Sword Wielder, unfurling to cast a dark shadow over the floorboards.

Levi watched the demonic aura stabilize around her, his lips curving into a satisfied smirk. “Then, welcome to the peerage of Levi Lucifer, Artoria.”

She looked down at her hands, feeling the dense demonic energy thrumming beneath her skin, before looking up at him with a bright smile. “Alright. Then please, allow me to reintroduce myself.”

She dropped to one knee, bowing her head in a flawless knight’s salute. “I, Artoria Pendragon, from this day forward, place my sword in your hands and bind my life to your will. Please treat me well, Master.”

The transition back to the Underworld was a jarring shift in atmosphere.

Levi sprawled out on the massive leather sofa in the first-floor hall of the Lucifer territory, staring up at the vaulted ceilings and heavy, gothic architecture that defined his ancestral home. He let out a long, drawn-out sigh, letting the tension bleed from his muscles.

“It feels like I haven’t been back here in a lifetime,” he muttered, rubbing his temples. “Even though it’s only been a few days.”

He had spent the first hour walking the perimeter, checking the upper and lower floors, letting the inherent security of the Lucifer Clan’s territory wash over him.

For Tohsaka Rin, Irisviel, and Artoria, the suffocating density of the Underworld’s ambient magic was a completely new experience. Kuroka, Shirone, and Sakura had taken the initiative to lead the newcomers on a grand tour of the sprawling castle, while Grayfia immediately set to work organizing the living quarters.

When the tour concluded, reality quickly set in for the newly appointed staff.

“Rin. Irisviel.” Grayfia stood before the two women, her posture rigid, her silver eyes sharp enough to cut glass. “Since you two have accepted the roles of maids within the House of Lucifer, you will adhere strictly to our rules. You will be maids who exhibit absolutely no flaws in etiquette.”

Her tone offered zero room for negotiation. To Grayfia, the maids were the direct reflection of the House of Lucifer’s prestige. A single misstep in etiquette was an insult to the family name, and she intended to monitor them with ruthless precision.

Levi watched the lecture from the sofa, entirely unbothered by Grayfia’s strictness.

“By the way, Irisviel,” Levi called out, shifting his weight. “Later today, I need you to set up the Great Hakurei Barrier that Grayfia recently improved. Establish it around the perimeter of the residence. From now on, the supervision of this territory’s defenses will fall under your jurisdiction.”

He then turned his attention back to his Queen. “The assets I asked you to prepare on your way back. Are they ready?”

“They are.” Grayfia nodded. She raised a hand, channeling a surge of pristine magic power.

The stone floor of the hall illuminated as a massive, complex blue magic circle expanded outward. The air hummed with energy as row after row of Einzbern homunculus maids, all dressed in immaculate, identical uniforms, marched out from the summoning formation in perfect, eerie synchronization.

“Irisviel,” Levi said, gesturing to the silent army. “The entirety of the Einzbern technological legacy belongs to us now, and I have no intention of letting such valuable assets collect dust. You will temporarily serve as the central control tower for this homunculus division. In the near future, I will contact a certain Magus to acquire a specific technique. If the integration goes smoothly, your consciousness will be networked across these homunculi, allowing you to freely shift your perspective and even switch bodies at will.”

Irisviel’s crimson eyes widened slightly as she took in the scale of the responsibility.

“You may bear the title of a maid,” Levi continued, his tone turning serious, “but your actual duty is the absolute security of the Lucifer Clan. The Great Hakurei Barrier, the command of the homunculus troops, the internal defense grid—all of it rests in your hands.”

The reality of their situation was grim. Vali and Rizevim had systematically gutted the Lucifer Clan, taking every active combatant and loyalist with them. The ancestral home was essentially a hollow shell.

Levi had considered recruiting capable Devils to fill the massive security void, but the Underworld’s political climate made that impossible. The population of high-tier Devils was strictly monitored. While Sirzechs might trust him, the other Satans would never sit idly by and watch the Lucifer Clan aggressively rebuild a private army.

The Einzbern homunculus technology was the perfect loophole.

These artificial constructs already possessed the baseline combat parameters to hunt magical beasts, placing their physical strength a cut above the average familiar. Levi had personally reinforced their spiritual cores using the Third Magic, and when combined with Grayfia’s Underworld-specific technical modifications, their combat power had been artificially elevated to the level of a battle-ready Low-Class Devil.

Individually, they were weak. But piled up in overwhelming numbers, they were enough to secure the perimeter.

“Alright. I understand.” Irisviel took a deep breath. She hadn’t expected Levi to hand her the keys to the castle’s defenses on her first day, but after rapidly calculating her own capabilities, she gave a firm, serious nod.

With the internal security delegated, Levi shifted his gaze to Tohsaka Rin.

He hadn’t recruited Irisviel and Rin simply to pour tea. The three main maids of the Lucifer Clan were designed to operate with a strict division of labor, forming the backbone of his operational framework.

“Rin,” Levi addressed the dark-haired Magus. “One of the primary reasons I brought you into the Lucifer Clan is to manage the communication logistics between the human world and the Underworld. You are going to be our bridge. You will act as the official liaison and the spokesperson for the Lucifer Clan when dealing with the Magus Association. With Irisviel locking down the internal affairs of the residence, and you managing our external human relations, Grayfia will finally be free to stay by my side and assist with higher-level operations.”

He paused, his eyes narrowing slightly. “However, with your current level of experience, you are nowhere near ready to handle those political sharks. For the immediate future, you will shadow Grayfia. You will watch, you will learn, and you will adapt. Can you handle that?”

The moment the words left Levi’s mouth, the casual tension in Rin’s shoulders vanished, replaced by a razor-sharp focus.

From the second she had signed the contract, she had been bracing herself for this life. Levi had always treated her with a strange, polite distance. Despite holding the absolute authority of a master, he had never once used his status to humiliate or pressure her. Now, he was handing her the diplomatic reins of a Satan-class household.

She met his gaze, her crimson eyes burning with absolute determination.