As a Grey Knight In Naruto

Chapter 49 – In the Flesh of Titans

The underground lab was quiet.

Hidden deep beneath Konoha, far below the village and the noise of daily life, Hajime stood alone. The walls were smooth stone, sealed by chakra and reinforced with metal. Bright chakra lights glowed overhead. Shelves lined the room, filled with tools, scrolls, vials of nutrients, and preserved tissue samples. This place wasn't a battlefield or a hospital. It was something else entirely. A forge, not of steel, but of flesh.

Hajime had already come far. In secret, he had created and implanted three powerful organs into his body: a secondary heart, the Ossmodula to shape his bones, and the Biscopea to grow his muscles. He felt stronger every day, his stamina lasted longer, his strength was increasing, and his control over chakra and psychic power had sharpened. But now, he had reached a point where simple progress was no longer enough.

The next stage of his evolution required something different. Something beyond books, scrolls, and chakra theory. The answer was inside him, but locked.

The gene-seed.

Inside every piece of gene-seed was more than just genetic material. It carried memories, echoes of the Space Marines who came before. When Hajime first received the gene-seed, he wasn't strong enough to access these memories. His mind would have broken under the weight.

But not anymore.

Now, his psychic power had grown. His body had adapted. And he was ready.

Sitting cross-legged in the center of the lab, Hajime closed his eyes. His body went still. Slowly, he reached inward with his mind, not just into his chakra pathways, but deeper, into the gene-seed itself. He could feel something hidden there, like a sealed door behind thick iron walls.

He focused.

Then pushed.

The door opened.

And Hajime's world exploded into light.

Suddenly, he wasn't alone. He wasn't even in his own body. His thoughts were flooded with memories, not one, not ten, but hundreds. Life after life. Death after death. He wasn't just remembering, he was living them.

He stood as a Grey Knight named Kael, charging into battle on a demon-infested world. His halberd burned with psychic flame. His armor cracked under the weight of a Greater Daemon's claw, but he didn't stop. He died on his feet, roaring a prayer to the Emperor.

He blinked, and now he was another. Vaeron, a Justicar. He stood at the top of a ruined temple, holding back a swarm of cultists and lesser daemons. His psychic shield crumbled, and he exploded in a burst of holy light, taking them all with him.

Another flash.

Now he was Thassor, a Librarian meditating in a hidden fortress, resisting the whispers of the Warp. He sat in silence for years, never speaking, never sleeping, only thinking and watching until the enemy appeared, and he burned them to ash with a single word.

More came.

A Techmarine named Alron, building weapons from alien metal. A scout named Drel, assassinating corrupted governors before their cities fell. Each life was short. Violent. Pure. Over and over, Hajime lived them, hundreds.

Their pain became his. Their training, his knowledge. Their victories, his pride.

Then, one stood out. Slower. Clearer. A Grey Knight in white armor with the red symbol of the Apothecarion on his shoulder. His name was Maladiel.

He wasn't fighting.

He was studying.

Hajime watched through his eyes as Maladiel walked through a massive chamber filled with floating diagrams and glowing tanks. He was deep beneath Titan, in the Apothecarion. He was reading something forbidden, files created by the Mechanicus scientist Belisarius Cawl.

The files described new organs. Better organs. Stronger ones.

Organs used in a new type of Space Marine: the Primaris.

The Sinew Coils that could make muscle stronger.

The Magnificat, which balanced the whole system.

The Belisarian Furnace, which gave second chances when death came too close.

Maladiel read every word. Then slowly closed the files.

"No," he whispered.

"These organs are powerful. But they're not pure. Not designed by the Emperor. Adding them would change what we are."

Hajime felt the thought like a cold wave. Maladiel believed that strength wasn't worth the risk. He feared the unknown. So, he locked the knowledge away.

Then, the memories faded.

Hajime gasped as he returned to himself. His body was sweating, his muscles trembling slightly, but his mind was calm. Clear.

He now carried the memories of ten thousand years of war. He knew every technique. Every battle tactic. Every organ. Every surgical process. It wasn't theory, it was experience. He had lived them all.

And more than that, he remembered the Primaris files.

Unlike Maladiel… Hajime did not hesitate.

He walked across the lab, where a scroll floated behind a psychic seal. It was the memory of the forbidden knowledge. Now that he had unlocked it, he didn't need keys or codes.

He opened it.

The data poured into his mind. Designs. Measurements. How the organs functioned. Where they went. What nutrients they needed. What side effects they caused.

He stood silently, staring at the scroll.

Then he began to write.

Using a brush and ink, he drew new diagrams. He combined the standard Grey Knight organs with the new Primaris ones. He modified the designs to match his human chakra system. He added warp-stabilizers to keep the energy flow safe. He improved their healing rates by using chakra pathways like the ones Tsunade taught him about.

It wasn't just copying anymore.

He was creating.

He looked at the final blueprint. A complete system. A fusion of psychic power, chakra control, and genetic mastery.

A warrior not just of steel and muscle, but of mind and spirit.

A being built to resist chaos.

To bring peace through unshakable strength.

To protect a world that didn't yet know it needed saving.

He stood tall, breathing slowly.

"I will become the first Primaris of the Grey Knights," he said quietly.

Not just stronger. Not just better.

Something new.

Something more.

The forge was ready.

And Hajime would build himself into a titan.

End of Chapter 49 – In the Flesh of Titans