While the materials for the golem were being delivered, Jin was talking with Beena.

"Beena, why don't you use the <> instead of just sending wind?

He gave her a hint of an idea,

"I see!　The wind blowing on the ice is cold!　It's comfortable even in summer!"

For some reason, Reinhardt was biting.

So Reinhardt and I put together the idea of a <>.

"In other words, we just need to blow air on something cold, right?"

"Then, why don't we make the shape here like this?

"Yes, then this is ......."

So, by the time the materials arrived, the three of us had completed the prototype of the <>.

"Ah, ...... is done, isn't it?"

"I think I've done .......

"I wonder if ...... is good enough."

Not only Jin, but even Reinhardt helped him with the <. No wonder Bina was concerned.

"It's fine, isn't it?　I was just helping out as a hobby," Reinhardt said.

Reinhardt said, and Hitoshi made it clear that he did not mind if this <> was Bina's work.

"Oh, thank you for ......, Mr. Reinhardt. Thank you, Jin!

Reinhardt thanked Bina apologetically,

Reinhardt said, "That's all right, Beena will make a good magecraftsman, by the way.

Reinhard said, "That's all right, but Beena will make a good magecraftsman. Beena, who was the one who had been told this, said, "I guess so," but her cheeks were slightly tinted with happiness.

"Well then, let's make a golem!

Jin is getting fired up in front of the materials that have arrived. Reinhardt has just brought in the Black Knight (Schwarzritter) and taken out the Magi Crystal for the control core.

"Well, then, let's fix it!

Reinhardt gets fired up, imitating Jin. With a little help from the Count, Bina is trying her best to learn from them.

Jin is still not ready to start work on the project. Meanwhile, Reinhardt has started to create a control core.

"Basic control magic formula (control system) writing. ...... write control formula for operation."

So Bina is sticking to Reinhardt so as not to miss the procedure.

"......Magic Control Flow (Magi Sequence)Good. ...... slave (master-slave) imprint."

The resulting control core.

"Okay, now the Black Knight (Schwarzritter) is back to normal. But it's boring as usual, isn't it?

I can't stop thinking about Jin's golem that I saw at Kunlun Island. Reinhard wanted to make the Black Knight (Schwarzlitter) more powerful.

"Besides, I don't want to lose again like last time.

We must not have the control core overwritten by powerful magic from the outside ever again. Since that time, Reinhard had been thinking of countermeasures.

"I wonder what is the best material that is hard to penetrate magic power.

Then he glanced at Jin and saw Erza sitting beside him, wondering when he had arrived.

"Oh, Elsa, I didn't know you were here. That's unusual, you never came to see me even when I've been holed up in the workshop.

When Reinhardt said this, Erza turned her head away.

"Well, well, you're a bit of a bore."

With that, she turned her attention back to the material in front of her and started to look for something. For the time being, there was the shell of an armored turtle, the leather of a large lizard, and the feathers of a helm eagle.

The idea is to select the material that is the most difficult for magic to penetrate from among these.

"It's hard to do it alone. ...... Hey, Erza, can you help me a little?"

Reinhardt called out to Erza, who was staring blankly at Jin's doodle of a golem concept.

Reinhardt smiled and turned to Bina, who was standing nearby,

"Beena, I'm sorry, but could you help me with an experiment?

He asked Bina to be his assistant.

She said, "Yes, if it's all right with me.

Reinhard then made samples from the three materials he had selected to be roughly the same size.

"Okay, turn your palm up."

He placed it on Bina's palm and then placed the plate on top of it.

"Now, write the <> magic on the plate on your palm.

"Yes, sir."

By observing the flow of magic power when Bina writes in this way, Reinhardt wanted to find a material that would dampen the magic power.

As it happened, it was a good thing that Reinhardt asked Bina to help him. If it had been Jin, he would have easily written the article regardless of the material.

Also, since Erza could not use engineering magic, she would naturally have to experiment with magic that is normally activated, and these are difficult to observe the magic power because of their short activation time.

"Hmm, the shell of an armored turtle is the most difficult to pass through magic. I guess I can use this.

Reinhardt thanked Bina and opened the chest of the black knight (Schwarzlitter).

The inside of the Black Knight (Schwarzlitter) is not simply hollow, but is filled with various kinds of fillings in various places.

For example, the fists are filled with steel to improve the effect of blows, and the toes are filled with adamantite to increase the destructive power of kicks.

The entire torso was stuffed with a spongy substance.

"Oh, um, Mr. Reinhardt, what is this?"

Bina could not remain silent at seeing the material for the first time and asked Reinhardt.

"Hmm?　This. It's called "goulashvam," and it's a demon that lives at the bottom of the sea, and the dried carcass is soft and resilient like this. It is a perfect material for protecting the control core, which is the heart of the golem, and other magical devices (magi devices).

But it is very easy for magic to pass through," he concluded.

Reinhard then takes out a magi device from the goulashvam and sets the control core he has just processed into it.

"Okay, <>...... good. Connect this to the operating system again.

The adjusted magi device is returned to the golem, and its surroundings are covered with the shell of an armored turtle. The black knight (Schwarzritter) was originally heavy, but the increase was not too great.

"Now it's just a matter of fine-tuning.

With 99% of the work done, Reinhardt begins to remove scratches and other damage to the exterior of the Black Knight (Schwarzlitter).

* * * * * *

"Okay, I've decided."

Jin, who had been studying the plan by drawing something that looked like a scribble on the wooden board at hand, seemed to have made up his mind, clapped his hands together, and stood up to get the materials.

At the same time, Reiko, who had been standing by Jin's side silently, also stood up.

"Father, what can I bring you?

"Well, I'll start with iron and zinc.

"Zinc?

Elsa, who had only been looking at him until then, raised her voice at the unfamiliar words. Jin noticed this,

"Oh, zinc is a metal that looks like lead but is not lead.

Jin explained simply. In this world, it is used to make brass.

Jin doesn't know what happens when zinc is mixed with iron, but he does know that plating the surface of the metal prevents corrosion.

"First," he says, "mix carbon with iron to make steel."

Carbon can be supplied from carbon dioxide in the air. Well, only Jin knows the existence of carbon dioxide. Carbon content is about 0.8 percent. The skeleton is made from it.

The skeleton is much simpler than that of a human being. For example, it has no ribs and no pelvis.

So this is what it looks like. Okay, heat treat. Hardening. Plating."

The same treatment as quenching and tempering is applied by engineering magic, and after further hardening and strengthening, zinc plating is applied to increase corrosion resistance.

Sliding parts such as joints are plated with adamantite to prevent wear.

The objective is to construct joints that are similar to those of humans. By building an endoskeleton and an armor-like exterior around it, it is possible to make it behave like a human being.

It is difficult to achieve this with an exoskeleton like a normal golem.

"It's kind of creepy.

Erza gave an honest impression when she saw the skeleton.

The simplest golem with a hollow interior is surprisingly inefficient in terms of magic power, since it uses magic power for all of its movements.

All of the golems created by Jin had an endoskeleton and were equipped with magical muscles for movement.

Pure magical movement is similar to telekinesis, but with magical muscles, the golem can expand and contract when triggered by magical power, thus increasing the efficiency of magical power.

"Magical Muscle" is a tool that can be used for the following purposes. <

I know what it is.

Sandworms are caterpillar-like creatures that live in the desert. They usually feed on underground magic, but when their territory is disturbed, they come out to the ground and attack.

No wonder Erza knows about them. Their leather is a specialty of the Shoro Empire.

As is typical of demon materials, it reacts to magic, so it has various uses, such as material for armor, sheaths and hilts for magic swords, and robes for mages.

The material is then torn into thin strips and bundled together to form magical muscle.

Just as Jin finishes this process, Reinhardt has finished repairing and remodeling the Black Knight (Schwarzlitter) and comes to check on Jin.