The holographic glow of the Artificer's data crystal filled the workshop, but Jonah's mind was elsewhere. He was back in the swamps of the Sunken City, watching the Hydra's mouth open wide. He felt the pain of a severed link, an echo of the moment he had sacrificed Shard.

He had won the battle, but the victory felt hollow. He had a team of three Progeny now – Rook, Nyx, and his new masterpiece, Specter. They were a perfect unit for stealth and assassination. But there was a clear flaw in their formation. A void.

He had no shield.

Shard, his loyal Echo-Shell Guardian, had been his first true defensive creation. It had been his protector, the wall he could rely on. Now, that wall was gone.

"You're thinking about it again, aren't you?" Vanessa's voice pulled him back to the present. She was looking at him with concern, her study of the ancient runes momentarily forgotten.

Jonah sighed, running a hand through his hair. "I need a defender. A tank. Something that can take a hit so the others don't have to."

"So, build one," Vanessa said simply. "You have access to any essence in the vault. We can design a Grade-3 or even another Grade-4 if we take the time."

"It's not that simple," Jonah said, his eyes turning inward. He focused on his Beast Space. He saw the three occupied genesis chambers that housed his Progeny. They felt stable, powerful. But he also felt… space.

"The Nexus Synthesis," he said slowly, the idea forming in his mind. "It didn't just create Specter. It stretched my Beast Space, made it stronger, more stable. I think… I think there's room to grow."

Vanessa raised an eyebrow. "What do you mean, room to grow? You have three Progeny. That's already more than most Tamers ever control."

"I'm not a Tamer," Jonah reminded her gently. "And this isn't about finding a new beast. It's about building a new room." He tapped his temple. "Another genesis chamber. A fourth slot."

Vanessa suddenly looked curious. "You think you can just… create one? Out of nothing?"

"It's not coming from nothing," Jonah said. "It'll come from me – my mana, my will. I have to build it."

This was a new frontier for his power. He had always focused on the creatures he created, not on the space in which they were born. But he now understood that his own internal development was just as important. His soul was the workshop; if he wanted to expand it, he had to be the one to lay the foundations.

"This sounds dangerous," Vanessa said, her voice laced with worry. "And probably painful."

"Probably," Jonah agreed. "Will you watch over me? Make sure no one interrupts? I don't know how long it will take."

She looked at him with a sigh in her eyes, but her presence never wavered.

"Of course I will. Just try not to break your brain, okay?"

Jonah gave her a grateful smile before settling onto a meditation mat in the corner of the workshop. He closed his eyes and sank into his own mind.

This was not a synthesis. There were no essences to guide him, no Genesis Core to act as a foundation. This was an act of pure mental construction. He was trying to build a house brick by brick, using only his thoughts.

He found the edge of his established Beast Space and pushed. It was like pressing against a wall of solid, unyielding darkness. There was no give.

He gritted his teeth, pouring his mana and his will into that single point. The wall didn't move, but he felt a sharp, stabbing pain behind his eyes. It was his own mind resisting the change.

He ignored the pain and kept pushing. For hours, he made no progress. It was a slow, brutal grind. Each push felt like screaming into a void. But then he felt something shift: a small crack. He had created a tiny dent in the psychic wall.

He focused on the dent, using his energy like a careful tool. He began to carve. He was trying to carve out a new space inside himself. Each bit he removed hurt like hell.

The first day crawled past in silence and pain. Jonah was completely still, sitting cross-legged on the mat. But a thin sheen of sweat covered his brow, and his face had gone pale. Vanessa quietly placed a glass of water and a plate of food beside him, her expression a mask of concern. He didn't touch them.

On the second day, he finally managed to carve out a small space. But it was unstable. The moment he relaxed his focus, the walls of his mind would try to collapse back in on themselves.

Now came the second part: strengthening it.

He began to weave threads of his own mana, forming a support structure around the new chamber. It was like psychic surgery, each thread needing to be placed with absolute precision. One mistake, one lapse in concentration, and the entire structure would crumble, the psychic backlash likely leaving him unconscious for a week.

He took his time, careful with every step. He built the floor, the walls, the ceiling, linking every part of the new chamber to his own energy. It had to be a part of him, as natural as his own heartbeat.

Vanessa watched over him, her own research completely forgotten. She became his silent guardian. When an instructor knocked on the door to check on their 'project,' she politely turned them away. She refreshed the water, replaced the untouched food, and monitored his vital signs with a small diagnostic spell. He was exhausted, his mana reserves running dangerously low, but his will was like iron.

On the morning of the third day, Jonah felt he was close. The chamber was built, its walls strengthened. All that was left was the final, critical step: linking it to the core of his power, making it a true and permanent part of his Beast Space.

He gathered the last of his strength, his remaining mana and pushed it all into the new chamber, not as a separate force, but as an extension of himself.

For a moment, the pain flared, white-hot and blinding. His entire mind screamed in protest. He felt a pressure building, a feeling like his head was about to explode.

Hold on, he told himself, his focus narrowing to a single, sharp point. Hold on.

And then, with a silent click, it settled into place.

The pain vanished. The pressure was gone. All that remained was a peaceful emptiness.

He opened his mental eyes and looked inside his Beast Space. He saw the three chambers, humming with the life of Rook, Nyx, and Specter. And beside them, carved out of the darkness, was a fourth chamber.

It was empty. It was waiting.

The effort had left him completely drained, but he knew he had done more than just add a slot. He had fundamentally upgraded himself. He had expanded his own soul.

He slowly opened his physical eyes. The world swam back into focus. Vanessa was kneeling in front of him, her hand hovering near his shoulder, her face etched with worry.

"Jonah?" she asked softly. "Are you okay?"

He managed a tired, victorious smile.

"I am," he rasped, his throat dry. "It's done."