"To begin, I guess that I need to talk about what is light, huh…" Arima muttered and mused for a moment. "Well, shit. It's harder to explain than I thought it would be," he grumbled and everyone sweat dropped.

After a minute of thought, Arima pointed at the light he had conjured earlier. "You see this light, right? It is actually produced by something we call electromagnetic waves; commonly composed of magnetic fields and electric currents. Fundamentally, an electromagnetic wave is viewed as synchronization of electric particles and magnetic fields, always perpendicular to each other and of similar oscillating speed.”

As he said that, a projection of a sinusoidal electrometric wave appeared in front of the students with a really detailed legend and explanation.

“To give you a crude image, think of water and fire. If the two are of proportional volume, they will produce steam as they both disappear. You can compare oscillation and synchronization to the increasing heat of the fire and the increasing quantity of water.”

“Electromagnetic waves can actually do a lot of things, and the visible light is only a small part of it. The type of waves/particles emitted is determined by their frequency of oscillation and/or their wavelengths. Incidentally, in my analogy, you can consider the steam, and the pressure at which it comes out, as the different ‘states’ which I will detail just after."

At this point, the smarter students could more or less follow if they really tried hard to assimilate the new knowledge and those who didn't understand still wrote it on their notebooks.

"Anyway, I won't go too much deeper on that. But remember, the light you usually see is produced by electromagnetic waves, and once the frequency goes over or below a certain limit, it isn't visible with the naked eye anymore. Additionally, it also starts to gain different particularities."

"Now, look at this," Arima waved his hand and something like a timeline was projected in the air. If someone from the modern world was here, they would most likely recognize this. It was the electromagnetic spectrum.

"A really small part of this line corresponds to visible light," Arima said and two points on the line were highlighted. "These two points represent a certain frequency, and between them, there is what we generally call light," he explained then looked at his students. "Do you follow so far?" He asked and everyone ‘kinda’ nodded.

"Well, just note it. You can ask me what you don't understand after. Following that, below visible light, well, when the frequency increases, there's ultraviolet, UV’s," he said and another section of the spectrum was defined. "But we won't talk much about it, and go straight below. At that point, there are X-rays."

"X-rays are ionizing. It means that they are very harmful to the human body, they can provoke serious illnesses and health problems. But you can easily protect yourself from it with magic. The most useful way of using those is like this," Arima uttered and waved his hand in front of Night.

A sort of gray screen was erected in front of Night and prevented the students from seeing his figure. Arima pointed at the light in the air and brought it behind the screen.

His sigil glowed and the light wobbled before vanishing. Then, a skeletal representation of a small wolf cub appeared on the gray screen.

The students exclaimed at such a strange phenomenon. "What I did here was using the X-rays to see Night's bones," Arima explained and dispelled the screen.

"X-rays easily go through the flesh and will make a black mark on the screen while when the rays pass through bones, which are denser, they will create a white mark, outlining the skeleton. The screen is usually made in metal. I just reproduced a similar effect."

"In my homeland, this technique was commonly used in medicine. But I want you to remember that it's highly dangerous to be constantly in contact with it if you are a normal human," he warned and everyone noted it.

"Next, there is the gamma rays. With a higher frequency and even more dangerous than X-rays. They're highly penetrating and can, not only weaken your body, provoke illness and mutations, but they also can damage internal organs and the bone marrow, which is essentially in charge of producing blood. So, basically; very dangerous.”

"Now let's go back to the visible light as a starting point. With a smaller frequency, you stumble upon infrareds." One part of the spectrum was once again defined. "Those are not really dangerous per se. They can be, but not as much as X or gamma rays. But infrared radiation is useful for one thing."

"To show you;" Arima plunged the room into darkness. "All of you, close your eyes," he instructed and everyone conformed. His sigil and irises glowed in red light and all of his students felt a warm feeling covering their eyes.

"Open them now."

When Arima said so, they all lifted their eyelids and exclaimed in surprise. Bright red. That’s what they were seeing. Their own bodies and the ones of their fellow students were now of different shades of red and orange.

"Okay," Arima’s voice resounded and light returned in the room. "What you just experienced was a thermal vision. Each source of heat releases infrared radiation. When you find a way to see those radiations, you can ‘see’ heat."

Arima waved his hand at the frequency scale. "The last one is microwaves. I'll be quick, these waves interact with matter and are usually used to heat things. But if you overload the quantity, it could do scary things," he grinned. "Things like frying your brain, for example."

The students gulped and Arima snickered.

"Anyway," he clapped. "The rest are radio waves and are not useful for you. For now, at least. The reason I explained to you all of this is because magic is always stronger when you know the principle behind it and no matter the magic, it’s always better to have a minimum of knowledge about what you’re trying to manipulate," he said and glanced at Ofia. She nodded with a serious expression.

"Well, that was the underlying process of how light is produced. Before continuing though, I have to tell you. What I just taught you is a scientific basis. People can have different understandings of light. They can even go completely sidetracked and view it from a completely different point of view. They could even create their own theories. But that doesn’t mean it’s wrong. Magic depends on your mind. As long as something is deeply rooted in you, it will be powerful. That’s what magic is all about, research, philosophy, and hypothesis," Arima stated and smiled.

"Now that this is said, let's talk about was the visible light can be used for from a scientific outlook."

"The first use I can tell you about is projection. The holograms I'm making to help you understand my lectures are an example of that. Now, as to how it works, I won't go in detail. But basically, the wavelength determines the colors following the Red-Green-Blue (RGB) pattern; you have to mix the colors to make another. Projections can be used as an alternative to illusions but you can easily see through it if you touch it."

"Second use; concentrated light or laser, if you prefer," Arima took out a metal plate from his storage and placed it in the center of the room. "Simply said, you gather light and condense it into one point," he described and pointed his finger at the metal plate. A bright light gathered and shot out from Arima's fingertip.

The laser pierced through the metal and left a hole on it. "Well, this one is not really new for you.”

"Third use; light is of course made to illuminate and blind in combat. It's also a good crowd control, as it can lead people on a battlefield. That's all you need to know about light's basic properties. Let's continue with magic theory."

"When you use light magic, the first thing that comes to you is purification. For example, for a spell of that nature, you usually use a chant similar to; 'Shine upon darkness, and expel evil'.”

"Of course, remember as well that light works better on darkness. So, to cleanse darkness, you usually use light. But it's also very good against death magic. Although its counterpart, life magic, is superior, light is still a huge threat against undead."

"Another example; 'Reveal the truth for my eyes to witness'. This kind of chant is basically used to destroy illusion arrays, mental ailments, and many others."

Each time Arima listed something, a hologram depicting the idea formed behind him.

"Well, it's pretty much what you need to know about light. So, because we still have time, I'll talk about darkness, which is the most complicated among the eight elements. But, although it's said to be the most intricate, it's also the plainest there is," Arima wryly said. "Because there's not much to say about it."

"I can't explain to you what darkness is. Because I don't even know if someone has already thought of darkness as anything else than a lack of light. The only thing you can do with the direct ability of darkness is simply to create shadows and maybe confront light. But in the end, darkness can't really be used in a first-degree application. Most of its potential can only be shown when you use theory."

"With a second-degree application, you can make of darkness your strongest weapon. It can become an endless pit, capable of absorbing everything. It can also attack people and rob them of everything."

"Darkness is often mistaken as evil, but it’s just too broad. The magic theory of darkness is basically everything that lurks in the shadows. And contrary to light, which can't secrete anything, darkness has a lot of things to conceal," Arima grinned and conjured a ball of darkness in his hand.

"It can hide anything because we can't see through it. It could be nightmares, monsters, pain, grief, death, and life…" As Arima kept talking, shadows kept emerging from the dark ball and loiter in the classroom. "And the most terrifying monster hiding in the darkness is none other than fear itself."

Arima declared and darkness once again invaded the classroom. But this one was a lot different from the previous times. It was cold and it made one shiver in fright.

"Darkness means a lot for humans. When you can't see anything, you generate fear. Loneliness, no light, no path, no escape. It means fear, sadness, sometimes anger, and at other times it’s despair. But you also find death at the end of the path," Arima slowly spoke and the obscurity was slowly dispersed.

At that moment, Arima swiftly observed every student. He was looking for people who didn't fall for the intimidation. Arister and Ofia were a given, and along with the others he had chosen, Arima found two others who didn't seem scared at all.

"Let me tell you this to finish. There's a lot of stories about people being malevolent and using dark magic. But the real reason for that is because darkness is more suited for them. Why do you think people turn out to be evil? It's not because they want it. They become evil for a reason. I’m not defending anyone. It’s just a fact. Everything has a reason. There's no such thing as destiny and pure coincidences. In fact, coincidences are actually phenomena of which we have forgotten the cause. That’s all."

"If I needed to answer why people sin, I'd just say because there are too many people who can't understand the difference between evil and good. That ignorant mass just keeps pushing people toward the path of good or evil without caring about the consequences. They just need someone like that.”

“They need evil people to fear, so they selfishly antagonize them.”

“They need good people to reassure them, so they selfishly acclaim them.”

“It's pathetic.”

"The reason why evil is generally connected to darkness is that, to efficiently use the latter, you need to understand this world. You need to feel the fear, the pain, and the death lurking around you. You need to accept everything and reject everything else. People who can do that are the smartest ones who always fail to find any reason to be a ‘good person’."

“You know, I consider myself to be quite nice,” Arima lightly laughed. “But I wonder why… my biggest affinity is darkness. I often accept to help those in need. But my methods are cruel and selfish. I cannot possibly stand on the ‘bad side’ since I would be disgusted to death but unfortunately, it’s the same thing for the ‘good side’. I cannot be neutral as well since I’m unable to be impartial for everyone.”

“And with all of that combined, I don’t deserve to be alive. Children, what do you think I am? If you answer this question, you might perform some groundbreaking improvements with darkness magic.”

The whole class fell silent. They didn't expect their teacher to suddenly talk about things like that. They listened to him from the beginning to the end and ended dumbfounded. On top of that, they felt the hidden meaning behind those words.

Was their teacher evil or good? This was a strange question. But they also felt how derisive Arima sounded when he talked about himself. They were all stunned beyond words.

Only Lanya and Night had melancholic countenances as they understood a bit of what he said.

Arima sighed. “I guess you need some time to think now,” he clapped and stood up.

"That's it for this lesson. Next time, I'll talk about the six other elements, don't worry they are simpler than these two… probably. You two, you can stay, the others, leave the place for the next batch," he commanded and the students dazedly left the room in the next moment.