As Elna stepped into the building, Leo followed quietly behind her.
From the outside it had looked grand, almost ceremonial, but the inside was surprisingly simple. The structure resembled an ordinary hall, wide and tall, with dark stone walls stretching upward into shadow. The only true difference lay in the details, torches burned along the walls with black flames instead of normal fire, their light flickering without warmth. In the center of the room hovered a shifting mass of shadow.
It was unstable, constantly changing shape. At times it stretched into thin tendrils, then suddenly folded into itself. Yet if one looked closely, its outline resembled a woman's figure, more precisely, Elna's figure, though unfinished, like a sculpture still being carved.
Leo watched her reaction before speaking.
"I tried to do for you what Selvanna, the previous owner of my domain, did for me," he explained calmly. "When someone first creates a domain, the process has to be slow. Your soul needs time to adapt to the power. If you rush it, the imbalance can damage you."
Elna's eyes continued scanning the hall, taking in every detail as she spoke. "But I still don't fully understand how the process works. I was trying to figure that out first."
"In the beginning," Leo said, "it's simpler than you think. You only need to will what you want, and Ethereon responds. The difficulty is control. Your will must be clear and limited. If your thoughts scatter, the result will scatter too. I placed protection rules around this place, but even with them, you shouldn't push too far."
They slowly approached the center of the hall where the shifting shadow hovered.
Elna stopped in front of it. "What is this?"
"In Arthur's and Luciana's buildings, that form represents a stable source of power they can draw from through my domain," Leo answered. "For you, it's still unstable because you haven't decided what your domain truly is. Your intent shapes its core. Until that becomes clear, it will remain like this."
The shadow flickered again, briefly forming a clearer silhouette of her before dissolving back into distortion.
After observing it for a few more moments, they walked toward the far end of the hall where another door stood.
Leo rested his hand lightly on the frame. "This door connects to your domain, the empty dark space you mentioned. I can't step through with you. From here onward, it should be you."
He looked at her seriously now.
"When you go through, focus on what you want your domain to become. Not what you think it should be. Not what others expect. What you desire. Ethereon will answer that. But take it slowly. Build piece by piece."
He stepped slightly aside, giving her space before the door.
"This is your foundation, Elna."
Elna nodded softly. Then she turned back to Leo and, without hesitation, wrapped her arms around him.
"Thank you," she whispered.
Leo returned the embrace, holding her for a few quiet seconds. He could feel her excitement, her determination, the slight nervousness she tried to hide. When she finally pulled away, there was a bright, genuine happiness on her face. Without another word, she stepped through the door.
The moment she crossed the threshold, her figure became blurry to him, as if she were sinking into a different layer of reality.
Leo stood still, watching. Then he felt it.
Something tugged at him, not physically, but deeper. A thread, thin yet undeniable, shot from beyond the doorway and latched onto his soul. It was not violent at first. It was simply there.
And then the pain came. It exploded inside him as if something were forcefully stretching his very existence. His soul trembled as a new path carved itself into it, the path of shadow. In that instant, he remembered, whenever someone's domain connected to his through those buildings, their path would link to him directly.
His domain was expanding. And so was his soul.
But expansion was not gentle. Leo dropped to one knee, gripping his left arm as agony concentrated there. The skin on his hand began to darken, turning pitch black as it hardened like layered scales. His nails lengthened into sharp claws. The corruption crawled upward, inch by inch, moving toward his wrist… his forearm… his shoulder.
He clenched his teeth. He had thought of every way to protect Elna. He had created rules of restriction and protection for her.
But he had forgotten one thing. Himself.
As the corruption reached his shoulder, the pain peaked, then suddenly something changed.
From the doorway behind him, white and red mist surged into the hall like a living tide. It wrapped around his body instantly, coiling around his corrupted arm. The dark growth halted. The blackened skin stopped spreading.
The pain began to fade. Slowly, Leo forced himself to stand. He lifted his left hand and stared at it. The fingers were still monstrous, blackened, hardened, inhuman.
His expression darkened.
Part of his soul had been wounded.
It wasn't entirely unexpected. He had forced too many powers into himself in a short time with Obscurae, the sudden surge of authority, the rapid expansion of his domain. Each gain had strengthened him, but none of it had been gentle on his soul.
He hadn't fully transformed, and he had stopped the corruption in time. Still, the damage was real.
The shadow path had carved itself directly into him, stretching his essence to make space. If more connections formed like this, each one would press further, reshaping him little by little. Eventually, suppression and illusion would no longer be enough to hide it.
He needed control.
Some way to filter these paths before they reached his core. A barrier or buffer inside his domain, something that could take the impact so his soul wouldn't have to. The problem was that he never heard a way to cure corruption.
But there was no time to dwell on it. Through the still blurred doorway, he sensed movement. Elna was returning.
The white and red mist wrapped around his arm once more. When it dispersed, his hand appeared normal again, smooth skin, ordinary fingers. It was only an illusion, masking the corruption beneath, but here, within his domain, the illusion was perfect.
No one would notice.
Not even his master, Alexia.
Leo straightened his posture just as Elna's figure became clearer beyond the door.
…
As Elna stepped through the door, she found herself once more in the dark, endless space she had always encountered when trying to shape her domain. Yet this time the emptiness did not feel distant or cold. It no longer pressed against her like something foreign. Instead, there was a subtle sense of belonging in the air, as if the darkness recognized her and bent slightly around her presence.
She turned and saw that the door remained behind her, its frame steady within the darkness. Beyond it stood a blurred image of Leo, watching. From that doorway, power flowed continuously into the space, not violently but with firm, steady pressure. It was clear that Leo had truly accelerated her progress; what once felt unreachable now seemed within her grasp.
Still, she understood the cost. This sudden increase in power would strain her soul, forcing it to adapt more quickly than it would have on its own. If she failed to grow alongside it, the imbalance could harm her. That meant she would have to continue training relentlessly, strengthening herself to match the foundation he had given her.
Keeping that in mind, she closed her eyes and began shaping her will. She pushed aside distractions and focused on a single, steady desire. She wanted strength, not for pride or ambition, but to protect the people she loved. That intention anchored her thoughts, and she held onto it tightly.
The space around her reacted almost immediately. She felt the darkness shift, as though listening, and she concentrated even harder to keep the forming structure stable. If her focus slipped, the creation could spiral out of control.
Gradually, the shadow began to tremble. The vibration spread outward in gentle waves, and after a few seconds, the shadows started to part.
From beneath her feet, stone emerged out of nothingness, smooth and black like polished obsidian. It spread outward in a perfect circle, forming a vast floor beneath her. Pale lines etched themselves into the surface, carving intricate concentric patterns across the marble as if guided by an unseen, ancient will. Then, from above, a thin pillar of cold white light descended and struck the center of the forming hall, stabilizing the structure and locking it into place.
Her domain was no longer empty. It had begun to take shape.
Columns rose next, one after another, thick pillars spiraling upward as their surfaces darkened and hardened. Veins of lighter stone threaded through them like frozen lightning, giving the structure both weight and quiet intensity. Between the pillars, arches curved into existence, forming slowly and deliberately, their edges sharpening as the darkness released its hold and allowed matter to settle into permanence.
The walls closed in last, sealing the chamber into a perfect circular hall. High above the doorway connected to Leo's domain, a massive round window unfolded in the ceiling. Its intricate lattice spread outward from a single glowing point, delicate yet firm, and through it a pale, ghostly light spilled downward. The remaining shadows withdrew to the edges of the hall, clinging to the stone in the corners as though reluctant to surrender completely.
Beneath the doorway, stone shifted again. Steps pushed upward from the floor, forming a small dais that elevated the entrance slightly above the rest of the hall.
When the trembling finally ceased, a grand hall of black marble stood where emptiness had once ruled. It was cold, immaculate, and silent, carrying the strange feeling that it had always existed and was merely remembering its true form.
But the creation was not finished.
At the center of the floor, shadows began to stir again. They rose like liquid smoke, pooling and rotating as if drawn by an invisible force. The movement quickened, tightening into a small vortex.
Elna only needed a single glance to understand. That power was hers. It resonated with her heartbeat, moved with her breath. It was not borrowed or gifted, it was born from her will. A fragment of her soul, given shape within her domain.
She slowly turned, taking in the hall once more. Compared to Leo's domain, this place was modest in size, perhaps no larger than his gathering hall, maybe even smaller. But it did not matter. This was only the beginning.
A soft smile curved across her lips as she faced the doorway again and began walking toward it.
…
Leo watched as Elna stepped back through the doorway, her figure becoming clear again inside his hall.
"That was quick," he said, raising an eyebrow slightly.
Elna smiled, a quiet excitement still lingering in her expression. "It felt different this time. The space didn't resist me. It felt like it already belonged to me, and as soon as I wanted something to change, it changed."
Leo returned her smile. "So… how do you feel?"
"I can feel my domain," she answered, placing a hand lightly over her chest. "It's like a current running through me. Strong… but I'm also really tired."
"That makes sense," Leo said with a small nod. "A domain is tied to the soul, but shaping it still consumes mana. You were building and stabilizing it at the same time."
Elna nodded, then her gaze lingered on him a little longer than usual. Her expression shifted, confusion replacing her earlier joy.
"Why do you look so tired?"
For a fraction of a second, Leo felt a flicker of surprise, but he masked it quickly. "It's nothing serious," he said calmly. "This was the first time I shared part of my domain with someone. It took more effort than I expected."
It wasn't a lie, just not the whole truth.
Elna continued to study him, worry flickering in her eyes. She knew him well enough to sense when something was off.
Leo gave her a reassuring smile. "Don't worry. I'll be fine."
And he meant it. The injury to his soul was real, but it wasn't beyond his ability to handle.
After a quiet moment, Elna finally nodded, choosing to trust him.
Then her gaze shifted past him and settled on the figure standing in the middle of the hall. The unstable shadow from before had changed. It no longer flickered or twisted randomly. Now it stood upright and defined, a dark silhouette shaped exactly like her, calm and still, as if waiting for a command.
"That power is stable now," she said softly.
Leo turned and followed her gaze. The shadow clone no longer trembled; its presence was steady, its aura controlled. It had accepted her will and taken form.
"Yes," he replied, his expression growing serious. "But you have to promise me something."
Elna looked at him. "What?"
"Until you reach S rank, you must never use that power." His voice was firm, and the concern in it was impossible to miss. "Luciana used hers when she was still A5, and it nearly killed her. The strain was too much for her soul to handle."
Elna glanced back at the shadowed figure. Even standing still, she could feel the depth of energy contained within it. It wasn't wild anymore, but it was vast.
After a brief silence, she looked back at him and nodded.
"I promise."
After that, together they left the domain and returned to their physical bodies.
Back in the room, Leo instinctively glanced at his left hand, half expecting to see the blackened corruption crawling along his skin. He was ready to cast an illusion to conceal it, but to his surprise, his hand looked completely normal.
The corruption remained, but only within his soul. It was visible in his domain, where his true essence stood exposed, not here in his physical body.
He let out a slow breath. That was good news, for now.
It meant he had time. Time to study the corruption, time to find a method to filter future connections, and perhaps even time to discover a way to cleanse what had already taken root. No one had ever successfully removed corruption once it marked the soul, but that did not mean it was impossible.
For now, though, exhaustion weighed on both of them. The strain of creation and connection had drained more than just mana.
Without further discussion, they decided to rest.
Tomorrow, there would be time to think.