Under his father's directions, Gravis named a lot of different materials and their properties. Though, since he didn't understand the underlying concepts, he could only quote what the booklet had said. One could argue if being able to recite all of this information was knowledge or not. After all, he didn't understand the deeper meaning of the materials. He could only quote something.

Gravis only knew the what, but not the why. Yet, a vast sea of what was required to understand the why. There was no way around this. After Gravis had recited the different materials and their properties for around two hours, his father grabbed a piece of ore.

"Look," he said.

BZZZZ!

A purely white bolt of lightning appeared and enveloped the ore in the air, and Gravis immediately felt the familiarity with this lightning. It was Punishment Lightning, the same lightning Gravis had. Yet, Gravis wasn't really surprised that his father could use such lightning. His father had also said in the past that people generally understood this lightning further down their cultivation path. This meant that there were a lot of people able to use it.

As the material floated in the air, the lightning bathed it, heating it up quickly. After a while, it started becoming malleable. Gravis knew the specifics of the material, so he knew how much power his father was using. On top of that, due to his affinity towards lightning, he could also feel the power with his being. It wasn't very strong. Gravis could create such powerful lightning without any issue.

Slowly, the ore started taking the form of a standard sword. After around three minutes, it had completely taken the shape of a sword. Yet, it didn't have sharp edges.

"You need to use your Spirit to form the material into a weapon," his father said. "It's quite a bit of stress on your Spirit and concentration, which is where your concentration training comes into play. You need to keep the finished product's shape in mind and use appropriate force with your Spirit. Too much, and you might damage its composition, too little, and it will break."

Gravis nodded as he kept looking at the sword-embryo.

"The edges of a sharp weapon need many times more concentration than just creating the weapon-embryo. When the material is much weaker than your current Realm, you can simply force it."

SHING!

In nearly no time at all, the sword's sides compressed, forming a very sharp cutting edge.

Whoop!

The sword reverted to its previous, dull form. "If you forge with such weak materials, you only need to force the borders of the sword into a sharp edge. At that point, depending on what material you used, you only need to follow the material's properties while cooling it down. Of course, I skipped the step of the Formation Arrays here."

BANG! BANG! BANG!

Many small thunderclaps resounded throughout the room as many small bolts of lightning concentrated on the edges of the dull sword-embryo. The normal lightning still kept the material at the appropriate temperature while the small lightning bolts put more force on the edges.

Gravis' eyes narrowed as he realized how much focus this needed. The small lightning bolts for the edges would also increase the material's temperature, and if it got too hot, its composition would change, making it worse. His father was moving the small bolts of lightning around so that they still put more pressure on the edges yet didn't make them too hot.

On top of that, his father was adjusting the balance of the remaining lightning to counteract the heightened temperature around the edges. This required a lot of subtle and minute movements. It was like a person doing four different things at once with their four limbs.

"If you want to forge something actually useful to you, you will be working with materials that you can't force into shape with your Spirit alone. At this point, you need to do what I'm doing right now. Use your control over lightning to compress the material around the edges without damaging it. It requires a lot of concentration and fine control to use this method effectively, but it's not nearly as consuming to your Spirit as the previous one."

Whoop!

Suddenly, the sharp edges vanished again to reveal the blunt sword-embryo again. When Gravis saw that, his eyes shone. "You didn't cut off part of the material to make an edge, but compressed it," Gravis commented.

His father nodded. "There are different ways to forge a weapon. Theoretically, you could grind the edges into a sharp shape, but that's not as effective as this method. Materials have different properties and can achieve different levels of power. That's referring to the Material Rank inside the booklet I gave you."

Gravis nodded. "This material is at the Early Unity Rank."

"Exactly. This means that the most powerful weapon you can make with this material is one appropriate for someone at the Early Unity Realm. Yet, you need to keep in mind that this is the upper boundary. It only shows the most powerful state of the material."

"Now," his father said, "If I were to grind it down like this,"

CRRRRRRRRR!

An ear grating sound appeared as the lightning hit the sword-embryo's edges diagonally, shooting outwards. A lot of particles shot away from the sword, leaving behind a sharp edge.

"This would only be able to become an Initial Unity Weapon. By not using compression, I haven't taken full advantage of the material. Of course, there is still one step remaining. There are still no Formation Arrays on the weapon."

"If I were to put the Formation Arrays onto the weapon perfectly, I would be able to create an Initial Unity Weapon. Yet, if I make some mistakes, the Formation Arrays might still work, but their efficiency will degrade rapidly. With this, the sword might downgrade to a Peak Spirit Weapon."

"Remember, the Material Rank only shows the theoretical highest Rank. This means that everything after that needs to be perfect to achieve it."

BANG!

The sword transformed into dust. "Now, it's your turn. We'll talk about the inscription of the Formation Arrays later," his father said.

Gravis nodded and pulled out one of the ores in the pile. He had chosen this one because this was not the first time he saw it. This was the ore that the lower world had called Core Ore, or Core for short.

Surprisingly, this ore was at the Initial Unity Rank. So, if everything went perfectly, it could become even a Unity Weapon. Yet, how could the lower world be able to do something as complicated as creating a Unity Weapon?

Gravis remembered the specifics of this ore and also its official name. It was called Low Ore. The reason for this simple name was that this was the best ore for weapons, which could be found in lower worlds. It was supremely rare in lower worlds but grew more and more common the more powerful the world became.

It was very cheap due to its abundance in the highest world and was the go-to material for everyone below the Unity Realm. It could be compared to standard iron ore for mortals.

Gravis made it levitate in front of him and envisioned a saber. He spent some seconds planning out every detail of the saber. Then, he summoned lightning in the air around the saber. Something like this had been difficult in the Spirit Forming Realm, but due to his higher control, it had become quite easy now.

The beginning wasn't hard since Gravis only had to heat the material slowly. He remembered all the specifics of the material and kept them inside of his mind. Keeping the disjointed information in his mind was way more exhausting than just understanding it by heart. Yet, in the beginning, there was no other way.

After some minutes, the ore started becoming malleable. Gravis stopped increasing the power and did several calculations in his head. He had to check all the details and behavior of the material to even estimate the current temperature. There were several calculations that took the behavior of the material into account to roughly calculate the temperature.

Gravis also had to include the usage of his Spirit and concentration in the calculations since they were the best indicator of how hard it was to manipulate the material. Gravis wished that he just had a thermometer for the temperature.

Though Gravis quickly realized something. Something as basic as a thermometer for forging should definitely exist. There was no way that no one had gotten the idea to make something like that. Yet, Gravis was also pretty sure that he could understand more about the material by only relying on his feelings.

The less help someone used while creating something, the harder it was. Yet, they got way closer to their work too. Tasks that some tools solved would help to create a better product, but the creator wouldn't understand as much about his work. He might not even know what the tools did, specifically.

Gravis started molding the ore slowly into a sword shape.

CRACK!

And tore the ore in two.

"What went wrong?" his father asked.

Gravis rubbed his chin. "I must have miscalculated. The fact that it broke apart meant that it was still too cold to mold properly. My calculations were wrong at some part."

His father nodded. "Right. Do you want me to tell you?" he asked.

Gravis thought about this for a second but then shook his head. "I should find it out myself. I might need to test several other materials and find the common cause of error. Another possibility is to just brute-force my way until I hit the correct temperature by feeling and then retroactively look at the calculations."

The Opposer nodded. "Good! Finding things out yourself is always better than someone telling you."

Gravis smiled and nodded.

And like this, Gravis continued smelting weapons.