Meanwhile, Nathan ignored Flora and Melissa in the distance and just chose to trust Flora. In the end, she shouldn't be foolish enough to be influenced by Melissa.
Visiting his teacher was a much more important matter, considering he needed a lot of ena before he could go on the mission.
"Master." Nathan nodded to Vivian, who was monitoring the cloud-repelling device in the field.
"What's wrong? It's unusual for you to come to me."
Nathan smiled wryly. "Well, I actually have a question. I wonder if it's possible to absorb a warrior class core or not."
"Warrior class? Are you insane?" Vivian raised her eyebrows before grabbing Nathan's wrist as if she was trying to check something inside him. After a few seconds, Vivian shook her head. "No. It's impossible. You don't have the capability to absorb the cores."
"Is that so?" Nathan scratched the back of his head.
Vivian looked at her disciple's disappointed face before asking, "Why do you want to absorb the warrior class core? If I'm not wrong, you can just give the warrior class cores to Flora or Noelle while you get a lot of mature class cores."
"Well…" Instead of answering, Nathan actually asked a question. "How do you actually find out whether you are strong enough to absorb a warrior class core?"
"Now that I think about it, you haven't learned about it yet in the academy, right? It's supposed to be taught in the second semester…" Vivian frowned.
"Yeah. The second semester didn't even start due to the eruption."
Vivian thought for a moment before waving her hand. "Follow me."
She brought Nathan into a small hut where she usually got some rest.
"Sit down in a way that makes you comfortable."
"Yes." Nathan followed her instruction, wondering what she wanted to do.
As soon as he sat down, Vivian explained, "Why do you think your body heats up when you absorb a core?"
"To swallow it?" Nathan tilted his head in confusion. "I mean, to absorb the energy within the core, which makes the body work harder?"
"Nope." She shook her head. "The answer is simple. It's to forge a path of your ena."
Vivian grabbed a stick and drew human anatomy on the ground. "In the beginning, a human doesn't have a storage for ena.
"This is why it's easy to spot a person who can become a summoner or not. Their bodies are naturally producing that amount of ena, but because there's no storage, it will keep leaking until proper storage is formed.
"The storage for this ena is formed the moment you undergo your first summoning ritual. It automatically establishes the storage, which keeps your ena contained.
"However, this is just storage. You can't use it because there's no path for you to utilize ena yet.
"Why do you think we are giving cores every month, especially right after the summoning ritual?"
In the drawing, there was only a single circle that indicated the storage. She pointed to the hands and all over the body while explaining, "Your body is unable to use it because there is yet an ena vein coming out of the storage.
"That's why when you first become a summoner, the only thing you can do is summon your familiar and have them fight for you. Summoning itself directly takes the ena from your storage.
"However, if you want to use the ena like an ability, there is a need to create a vein to channel the ena from inside your storage to the outside." She drew veins all over the body.
Nathan instantly noticed what was going on. "Ah. So, you gave us the cores to create that vein?"
"Yes. The ena from the core is actually flowing frantically inside your body. I'm sure you notice that the first time you swallow a core, your body heats up more than the second core and so on."
"Indeed." Nathan nodded in confirmation.
"That's because the ena from the core is moving all around your body, which ends up creating the veins. And they'll ultimately reach and settle down inside your storage.
"Once the veins are created, you swallow more and more cores, which causes the ena to rampage inside those veins, ultimately widening them up.
"This is how we usually create the ena veins and enlarge them. If you swallow multiple cores at once, the rampaging ena will also be multiple fold, which results in your body heating up even further.
"Even though we don't teach the students about the veins right away, we have warned them not to take the mature class core, right?
"That's because their bodies won't be able to withstand the rampaging ena from the mature class cores, which is several times higher than the juvenile class cores.
"And we teach them in the second semester because at this point, they will begin to search for juvenile class cores and a lot of talented students must be thinking about going to find a mature class core. Most of the time, it will be the upperclassmen that will be bringing you to hunt down mature class aliens.
"That's the reason behind the principal's six months of immunity as well. Even though the Frexia Academy seems lax, all the established systems from the cores given by the academy to the events have been refined for over a hundred years, so there's actually a meaning behind each of them.
"Of course, there are geniuses like you and Selena, who are able to hunt down mature class cores before the time, but because you're my student and Selena is also good enough, I didn't really need to tell you about this. Usually, we would have approached these people individually to explain it. Or their respective teachers will be responsible for it.
"To widen these veins, you just have to swallow cores in a large amount. This is the normal method. However, you can forcefully enlarge it by using other methods. My method is to use herbs, which is what you've been taking this whole time.
"However, it's still not enough to absorb the warrior class core. After all, you can imagine a small particle going up and down frantically within your veins. If that particle has enough energy, it might puncture your ena vein."