#5

Mufasa lifted the beheading sword, weighing it in his hands.

"Three kilograms heavier than before… Looks like sandworm blood has a higher metal content than human blood."

Satisfied, he raised the sword—then, without hesitation, snapped it in half.

Gaara caught the first half Mufasa tossed his way. Without a word, Mufasa plunged the remaining broken blade back into the sandworm's blood vessel.

A sandworm's blood made up about 8% of its body weight.

That meant a single 100-ton sandworm carried 8,000 kilograms—8 tons—of blood.

But unlike human blood, sandworm blood was rich in metal.

Mufasa's calculations were simple: it only took 20 kg of this blood to generate 15 kg of refined iron.

Which meant, in total, a single sandworm could produce around 6,000 kilograms of metal.

Enough for:

12,000 kunai (each weighing 0.5 kg)

4,000 ninja swords (each weighing 1.5 kg)

Of course, draining a sandworm dry would be wasteful.

Mufasa had four of them in the nest. By taking turns drawing one-third of their blood each day, he could sustain a steady production of 2,000 kg of metal daily—totaling 730 tons annually.

Compared to the industrial world, that was nothing. But in the ninja world? That was a revolution.

Especially for Sunagakure, a village without its own steel production. Every ounce of metal had to be imported.

And now?

Mufasa had built the first stable supply of homegrown iron.

No more costly purchases. No more struggling to refine minuscule amounts of metal from the desert.

Just feed the sandworms, and they would bleed iron.

It was almost too good to be true.

A smirk tugged at the corners of Mufasa's lips. The more he thought about it, the more excited he became.

He continued stabbing the beheading sword into the sandworm, breaking and reforging it over and over.

Night fell.

The sandworm beneath them squirmed, growing restless.

"Boss," Jakis called out, concern in his voice. "It's had enough. Any more, and we might kill it."

Mufasa finally snapped out of his trance.

The sandworm writhed, its body shuddering from the blood loss. Even with anesthesia, it was struggling to stay still.

"Temari," he called.

"On it."

She swung the giant fan off her back and with a single powerful gust, sent a storm of wind whipping through the herd of cattle and sheep.

The animals were lifted into the air, tumbling helplessly toward the sandworm's gaping maw.

It didn't hesitate. Its massive, four-petaled jaws opened wide, sucking the livestock in like a bowl of noodles.

With its hunger satisfied, it calmed down.

Mufasa, Jakis, and Kankuro floated back to the ground.

Gaara approached, arms crossed. "Total yield: 2,300 kilograms of iron."

Neatly stacked around them were piles of half-forged blades, gleaming under the moonlight.

Kankuro ran a gloved hand over the raw metal, analyzing its quality.

"Boss, this stuff is tougher than the iron we've been buying. If we use it to make ninja tools, their performance will definitely improve."

He frowned, rubbing his chin. "But there's a problem. I tried melting it down in the blast furnace, and it needs over 1,500 degrees just to become molten iron. And even then, once it cools, it just reverts back to its original shape."

He sighed. "What do we do about that?"

Mufasa already knew the answer.

He had spent enough time studying the beheading sword to understand its secrets.

The blade was forged using a rare metal with a memory function. That, combined with specialized ninjutsu, allowed it to absorb iron and regenerate itself.

In other words, the beheading sword wasn't just a weapon.

It was a scientific ninja tool.

The original forger might not have understood the science behind it, but they had stumbled upon something incredible.

Mufasa grinned. He could replicate that knowledge—no, he could take it even further.

"Simple," he said. "We keep heating it. Destroy the internal structure completely, then force it to stay in a molten state."

Kankuro blinked. "Uh… that sounds easier said than done. Our current blast furnace barely reaches 1,500 degrees."

"Then we'll build a bigger one," Mufasa declared. "A higher furnace. An assembly line. A full-scale factory."

Now that he had a stable supply of raw materials, there was no limit to what he could accomplish.

And in the ninja world, construction wasn't a problem.

They didn't need laborers.

Mufasa walked two kilometers away from the sandworm nest, stopping at a flat stretch of desert.

Gaara, Kankuro, Temari, and the others followed, watching in silence.

Mufasa hovered in the air, extending his hands.

He took a deep breath.

Then shouted—

"Earth Style: The Art of the Factory!"

The ground rumbled.

The earth cracked and split apart.

A massive rectangular structure, 200 meters long, 40 meters wide, and 30 meters tall, rose from the sand, shaping itself into a factory building.

But Mufasa wasn't done.

"Electromagnetic Release: Reinforcement Technique!"

Iron and metal elements in the sand were drawn toward the walls, fusing into steel reinforcements.

The desert wind howled, sweeping away the dust.

And when it settled, an 8,000-square-meter factory stood before them—fully formed.

The first industrialized ninja tool factory in history.

Mufasa turned to his team, eyes gleaming.

"Welcome," he said, "to the future of ninja warfare."