The next day, Arima continued his lecture about elements. "Today will be about fire, I guess."

"You may already know it since it has been proven with magic by scholars; the air we're breathing is composed of different gases. Now, one of these gases is the fuel with which fire burns naturally. From where I come from, it’s called oxygen and the more oxygen there is, the stronger the fire will be."

Arima created a light projection and numerous blue circles were illustrated in it. "These circles represent oxygen," he said and then the depiction of a flame appeared. As the fire burned the blue spheres were slowly going toward it to disappear soon after.

"So, if you want to raise the power of your fire magic, you can do this," the projection changed. This time, the blue spheres started gathering together in a single place, then a small flame ignited them all and created an explosion.

The students exclaimed like they understood something and noted it down. Especially the ones who had already some understanding of it as fire mages.

"Of course, it's only in the case of a natural fire. With magic, once you're around the fifth level, you can replace oxygen with mana. But even in that case, this theory still works."

"Also, like most of the elements that can be condensed, fire can be compressed to create destructive bombs, like this one." Arima waved his hand and red marble appeared in his hand. Everyone looked at him with puzzled eyes and the latter laughed.

"Would you believe me if I said that this marble has enough power to destroy at least everything in a hundred-meter radius?" He asked and every student cried inwardly.

Arima smiled at them. "Well, that was fire's practical use. As for its magic theory, it's another story. There's not really a specific theory for fire. Actually, it's also a very special element since it can be the bane of every other element. The magic theory of fire is straightforward. It's just burning."

"That's what you call the fire theory. Flames that can burn everything. A fire that consumes light, burns darkness, disperses wind, crumbles earth, evaporates water, consumes lightning. That's what the flames can do. Turn everything to ashes. Fire can also purify; it can even bring happiness and rest to those who can extract fire’s most gentle properties."

"Fire can also give life and represent passion. It has followed humanity since the beginning of times. Obviously, its theory is very powerful and omnipotent," Arima declared and cleared the projection.

"Next will be water then," he announced and then his expression darkened a bit. "Now that I think about it, I'll need to talk about molecules…" He muttered and Night tilted his head.

"Hm, okay…" Arima gathered his thoughts. "There are two elements composing water. One is what I mentioned earlier, oxygen, and the other is what we call hydrogen. When those two elements join together, they create microscopic elements of water called molecules. Ultimately, water is a congregation of molecules," he explained with a frown on his face and when he finished, he sighed.

"Do you understand?" He asked and all of the students nodded this time. "Then it's fine. Next, as you all know, water can take three different states; liquid, gaseous, and solid. What I want you to learn in this lesson is that water doesn't necessarily require a change of temperature to change form. At least with magic," he stated and Isla's eyes widened in shock.

"What does that mean?" She asked. Her forte rested on water magic. She always changed its state by thinking about the change in temperature.

"The explanation lies in the molecules. When water is heated, the molecules are agitated and start receding from each other. It's when the distance between each molecule is too big that the water is in a gaseous state. As for ice, when the temperature falls, the molecules approach each other, and their agitation slows down. So, you can view ice as the molecules stuck together or very close to each other," Arima explained and created holograms explaining the two phenomena. He then looked at Isla.

"That's why it's better to think about the change of state based on the molecules. When you think about it as a change of temperature, more mana is needed and also, when you think about heating, you start thinking about fire. Unless you have an equal affinity with fire, it will undoubtedly impede your water magic," he added and Isla stared back at him agape.

She stood up and immediately left the room to test it out. Arima just watched her go and smiled.

"Well, let's continue with the magic theory of water. I'm sure Isla already knows about it, so I won’t wait for her."

"To be honest, the three states of water can be used individually for magic theory. In liquid form, you can clean, drown, and isolate. But let's be honest, the liquid form is better used with the first-degree application, with compression and pressure, it's a very good destructive weapon."

"Then, what about its gaseous form? Well, there's not much use in the first-degree department. But with theory, you can make things such as illusions and displacement magic. Mist can also be used as surveying magic because it can effectively fill a very large volume."

"Then, we have ice. It's the strongest weapon of water magic users. It’s sharp and solid. And even if it isn't needed to think about the temperature when you create it, it's still extremely cold and you can freeze anything with it. The magic theory is not that varied, but it's the best on one aspect compared to the others; seals. Eternal, cold, and sturdy prisons."

Arima explained in one go the most important aspects of the three states of water.

"Let's continue. I'll talk about lightning magic now. First, let me tell you, lightning magic is my principal specialty. But my understanding of it is not really different from the others," Arima said and the students were very enthusiastic to hear about his field of expertise.

"In natural circumstances, lightning is produced by a particular phenomenon. I will try to simplify what’s following as much as possible. In our world, there are particles called electrons and protons. Electricity is usually produced by a flow of electrons only. Basically, when electrons move from one place to another, they generate electricity. Remember that."

"Now, back to lightning. It's a discharge generated between electrically charged regions. Between two clouds in a thunderstorm, for instance. But it also can be between the ground and the clouds, or within a single cloud. I'll show you an example," Arima declared and stood up.

He spread his hands out and in each of them, some electricity appeared. Arima slowly brought his hands close to each other. When they were around half a meter close, sparks started appearing between. And suddenly, a miniature lightning bolt connected his two palms as thunder roared in the classroom.

"Ah!" The students shouted and covered their ears. When they looked back at Arima, he was already sitting down on the desk, observing them with a teasing smile. At that moment, they all felt very embarrassed.

Arima laughed lightly and created a projection showing three situations; lightning between clouds, within clouds, and toward the ground. "I won't explain to you how the clouds are charged because it's a bit more complicated and it needs a lot of details. Just remember that lightning is produced by two charged regions 'interacting' with each other."

"Also remember that lightning magic isn't all about lightning but also electricity. The former is for destruction and the latter is a bit more delicate if I can say so. Anyway, let's follow with the first-degree application."

"There's not much to say actually. Lightning is the most destructive element. Even surpassing fire and light when it comes to pure demolition. It's also very fast. With electricity, you can do a lot of things as well; electrocute, create physical weapons and platforms, use magnetic fields, and you can even invoke electric familiars," Arima stated as he summoned a small electric bird which he let fly around the room.

"Lightning is a very versatile element, almost perfect in defense, attack, and speed at the same time. It also has no particular weakness when facing other elements except earth. But it’s quite hard to control overall. Now, what about the magic theory? It's a bit similar to fire. As long as you give a good image and theory, lightning can pierce and electrocute everything. It has even the ability to damage the abstract and the ethereal. It's also a fact that lightning is even older than the fire in history. It is said that humans learned how to use fire thanks to lightning. There are also numerous legends about powerful lightning divinities."

"One of those divinities is the renowned King of Gods, Zeus. Ultimately, this gives quite some power to lightning magic’s theory."

Arima said and checked the time. "Let's finish this lecture with spirit magic. Since it's a special element only pertaining to the world of magic, it doesn’t have any scientific explanation. So, it should be quick."

"Each matter in the universe produces spirits. Fire generates fire spirits. Water creates water spirits and so on. Spirit magic basically allows the caster to control the spirits around him for his own use. That's why spirit magic users possess the best versatility in all of the magic world. But in exchange for that, there’s no magic theory. The only theory you can use with spirits is infusing; directing spirits into a weapon or an armor to reinforce them to a very high level."

"It might sound like an ineffective magic, but it's actually terrifying when you use it correctly. Unfortunately, this is a kind of magic that thoroughly depends on your talent and how much nature favors you. Even I, who technically has an affinity with it, can’t use it because I’m barely able to make spirits listen to me," Arima finished by saying that and shrugged.

"That's it for today, come back tomorrow," he dismissed his class and unswervingly left the academy with Night and Lanya.

That day, once again, people heard of the things Arima taught about. Even renowned scholars were enlightened by his words.

The evening of that day, our trio was dining at the Inn with Arister. "You… aren't you stronger than before?" The latter asked and Arima smiled.

"Yeah, things happened. It was unexpected, even for me."

"Unexpected…" Arister smiled wryly. "If I'm not wrong, you went up by around two measures. You’re at least five times stronger. How much would that be? Two skies? What kind of ‘unexpected’ is that?"

This time it was Night who laughed. "You're right. But this guy is the verbatim definition of unexpected. So, if you hear that word from his mouth, then just take it as a miracle."

Arister sighed and shook his head. "At this point, can't you already beat that Earthen God alone?"

"Well," Arima mused. "Maybe? If I resonate and use the One Thousand Parade whilst in my undead form, I may even not need to use the Omni Form."

Arister blankly stared at him. "Sorry, I can't understand a thing of what you're saying," he uttered and Lanya giggled.

"Yes, I can beat him already," Arima summarized right after.

"Well, congratulations, I guess. I think that I can break through soon as well. Your lessons are genuinely useful."

"Oh," Arima smiled. "You learned something?"

"Well, who wouldn't after listening to that? My forte is darkness and considering what you said, I may actually be leaning toward the ‘evil path’,” Arister snickered. “Your explanation earlier, although short, was really instructive. Thanks for that."

"There's no problem," Arima responded. “It’s my job at the moment, you see.”

"True. But, to be fair, the limit-break technique you introduced is still probably the most useful thing I learned from you. It's a terrifying skill capable of killing stronger foes."

"I admit that it's quite useful,” Arima nodded. “Well, there's also the soul contract. But for you, it's rather useless since you already have the inheritance of Ares. By the way, how does your inheritance materialize? Ares is a god of war, right? I’m honestly curious."

"Ah," Arister smiled. "Do you want to see it?"