The next day, the students were still running around the field according to Yohan's instructions.
The students did not feel it, but there were fewer dropouts than the day before.
Mi-yeong sat in the stands of Class F's field and watched them.
At first, the Class F students had found it strange that Mi-yeong of Class S was here, but now they had grown used to it.
"Are you not going back to your class?"
"I won't go until you spar with me."
"You're not even using polite speech anymore."
Behind Mi-yeong, who was looking at him innocently, a Class F student running laps called out to Yohan.
"Huff, huff. Class President."
"What?"
"You went out last night. Where did you go?"
"I had something to take care of for a bit."
"Something to take care of?"
"Don't try to know too much. Knowing will get you hurt."
Between Yohan and the Class F students running laps, Instructor Haru approached.
"Your uniforms already smell horribly of sweat this morning."
"Please call it the result of training."
"You know you have to buy uniforms with AP too, yes?"
"I know. I will prepare spare uniforms. Do not worry about uniform costs, my friends. So you know what that means, right?"
The students, knowing it meant they had to keep rolling hard, merely sighed in resignation.
"Understood. Then I will explain today's class."
"Here, not in the classroom?"
"Yes. Today's class will be held here on the field. Because we will be forming mana hearts."
At the words "mana hearts," the students began murmuring.
‘Mana heart. This will be the first step to reviving my own Shadow Unit. All of Class F must create mana hearts my way.’
A mana heart was a basic necessity a Hunter had to possess, a core made of mana that was like a second heart.
"Before the upcoming exam, you must form mana hearts."
Mana heart.
That was a basic quality for one who would become a Hunter.
Hunters, who used mana in order to wield Ego Weapons and their abilities, were fundamentally unstable if they relied only on mana from nature.
What had been devised for that was the mana heart.
When the first Hunters, the Twelve Families, formed mana hearts, their physical abilities grew by leaps and bounds, and they could use techniques more stably.
In other words, monsters became even greater monsters.
***
In his previous life, even the Shadow Unit, an assassin group meant to kill Hunters, had trained to create mana hearts.
It was the minimum condition for ordinary people to face Hunters.
‘Iron rule of the Shadow Unit. If you have no heart, kill the enemy with the self-destruction of your mana heart. If you have no mana heart, kill the enemy with your living heart.’
It was a cruel iron rule of the Shadow Unit: harm the enemy by any means necessary.
"To create a mana heart, you must first sense mana."
The leader of the Shadow Unit shouted as he looked at the members, including Yohan.
"However, you will not be capable enough to sense mana. Therefore, our liege, the Hangeom Family, has bestowed grace upon our foolish selves!"
The leader of the Shadow Unit took out a potion, a crystallization of pure mana, from inside his chest.
"The method is simple! Until you sense the mana in the atmosphere, this precious potion will be poured into your mouths."
The leader of the Shadow Unit personally descended from the platform and approached a member kneeling on one knee.
Then he handed him the potion.
"Drink."
When mana suddenly rushed into a body that could not accept mana, the body began to swell.
"Endure."
Because of the massive amount of mana, his blood vessels began swelling blue, and his skin turned blue.
His body swelled larger and larger, then his eyeballs burst, and black blood poured from his mouth.
Thump.
Looking at the member who had collapsed just like that, the leader spoke.
"He fell into mana poisoning. A failure, then."
Then he took one more bottle of potion from inside his chest and fed it to the next member.
That member who drank it also fell into mana poisoning and lost his life.
Even so, the Shadow Unit maintained their kneeling posture.
When Yohan's turn came, he swallowed the entire potion without the slightest fear.
When mana flowed through his body, Yohan began controlling his body, which felt as if it would explode.
‘I cannot die like a dog here!’
Yohan exhaled for a long time.
Blue breath leaked from his mouth.
His fingertips turned blue, and his heart pounded violently.
Only after enduring like that for an hour was Yohan barely able to calm the overflowing mana.
Relieved that he had survived, Yohan lost consciousness and collapsed.
"What extraordinary mental strength. Take him away and make him drink one bottle a day. Until he senses mana."
***
‘Back then, I went through three years of hell trying to sense mana with my bare body.’
Yohan in his previous life had literally been an ordinary person.
He had to create a mana heart without being a Hunter.
But now, things were different.
He had an Ego Weapon, proof that he had Awakened as a Hunter.
Whether one had an Ego Weapon or not made a great difference in sensing and absorbing mana.
To put it simply, an Ego Weapon not only possessed the ability to function as a weapon, but was also a medium that resonated the body and mana.
Yohan looked at Haru and asked,
"Instructor, we only need to create a mana heart, correct?"
"Yes, that is correct. That is the goal of this class. However, it will not be easy. First, you must sense the mana in the atmosphere and...."
As soon as Yohan heard Haru's words, he closed his eyes.
He could only feel the direction of the wind. Mana could not be sensed.
"Yeongcheol."
Yohan extended his hand and summoned Yeongcheol.
Then he drove it into the ground.
He knelt on one knee and took one deep breath, and mana began flowing into Yeongcheol as if lightning had struck.
‘It took me three years just to sense mana before, and now I can do it in such a short time. As expected of an Ego Weapon.’
Yohan seized the mana flowing in.
Blue mana wrapped around the pitch-black Yeongcheol.
Seeing that, Haru could not hide her shock.
‘The explanation is not even over yet.... He already grasped mana!’
Yohan calmed the pulsing mana inside Yeongcheol.
At that, the uneven mana stabilized, adjusting itself to the size of the blade.
Then Yohan slowly began accepting the stabilized mana into his body.
‘From the blade to the hilt. Next, through the palm, the forearm, the shoulder, and into the back.’
Haru swallowed as she watched Yohan's mana heart formation proceed smoothly.
"Just a little more! Let the mana flow into your body like that! While focusing on your heart!"
As Haru said, a mana heart was supposed to be formed in the heart.
A mana heart formed in the heart stably sent mana throughout the entire body.
‘But that is only an outdated theory done the same way as everyone else.’
Yohan pulled the mana flowing toward his heart.
At that, the mana formed into a round sphere in the right side of his chest and settled there.
"Yohan!"
Ignoring Haru's instruction, Yohan formed his mana heart in the right side of his chest.
At this rate, he would become crippled from mana poisoning and be unable to continue life as a Hunter.
‘Ah... to lose such talent here...!’
But Yohan's mana heart, fixed into a round sphere, was stable.
‘What is this?’
The mana did not eat away at its owner's body, but obediently carved itself into him.
"Hoo."
As if he had finished everything he had to do, Yohan pulled Yeongcheol out and rose from his place.
Instructor Haru looked at him with an expression of disbelief.
"That level of understanding of mana hearts and that speed in forming one.... What are you doing with that genius of yours?!"
"Is there some kind of problem?"
At Yohan's innocent question, Haru was dumbfounded.
"Of course there is! Ha, Student Yohan? Why did you not create your mana heart in your heart?"
"Because this is more efficient, Instructor."
"‘Efficient’?"
Haru could not understand Yohan's words.
The mana heart had been developed by the Twelve Families, the first Hunters.
Their method was orthodox, and the method that produced the highest efficiency.
A mana heart was, literally, a heart that made it easy to circulate mana within the body.
If it was destroyed, not only would one be unable to use mana, one would not even be able to sense it.
In other words, life as a Hunter ended there.
"How is that efficient? What the student just did was only increase the number of vital points to two!"
"Vital points.... Instructor, do you know what advantage there is in creating a mana heart in the right side of the chest?"
Instructor Haru had also seen a certain scientist's thesis before, so she knew the theory.
The title of the thesis.
However, it was said that the theory had never actually been used because it was far too impossible and absurd.
Because creating a mana heart in the right side of the chest meant ‘death.’
"Are you asking me that?"
"Because I thought that if it is you, Instructor Haru, the Mana Specialist Instructor, you would understand my intention."
"Very well. To explain it in a way that everyone here can understand...."
Haru summarized the thesis she had read in her head and spoke.
"When mana is placed separately in the right side of the chest, the advantage is that the size of the mana heart can grow beyond the size of the heart."
Jung-han raised his hand and asked Instructor Haru a question.
"Why is that an advantage?"
"What do you think happens if the size of the heart grows larger?"
"Blood moves faster?"
"That is correct. It is the same concept. If the size of the mana heart grows larger, not only does the amount of mana one can hold inside the body increase, but the speed at which it spreads also becomes faster."
"It only sounds good...."
"Good? This is nothing but honeyed words!"
Yohan judged from Haru's reaction that she knew about the thesis.
Yohan had also read that thesis.
The flaw of this thesis was that it was aimed solely at Hunters.
The researcher at the time had not gone so far as to imagine ordinary people possessing mana hearts.
Ordinary people could not grow by leaps and bounds like Hunters, so there was a limit to their growth.
That was why there was no chance of them falling into mana poisoning, nor any chance of them dying after the formation was complete.
They merely died in the process of sensing and forming mana.
‘Of course, ordinary people have no reason to form mana hearts, and they cannot form them in the first place.’
Instructor Haru shouted, trying to deny what Yohan had done.
"If you hold more mana inside your body than you can handle, you fall into mana poisoning. When that happens, becoming crippled is the basic outcome, and in most cases, you lose your life!"
Even as she said that, Haru's heart began pounding fiercely.
She might be able to prove a thesis theory that no one had ever been able to test until now.
Would she protect the students' safety as a teacher, or prove the thesis as a researcher and contribute to the advancement of society?
The conflict raged in her head.
While Haru was conflicted, Yohan thought,
‘What if this mana heart combines with Predation? I can grow endlessly.’
Thinking of becoming even stronger in the future, Yohan felt inwardly elated.
To him, mana poisoning was not even an obstacle.
If he was poisoned, he would simply remain poisoned, but he was certain that would not happen in the first place.
That was because he had succeeded in bone-deep rebirth through the pill and Awakened as a Hunter, making him an existence different from ordinary Hunters.
"Student Yohan! Why on earth did you do something so reckless?"
"Did you not say so yourself? This heart can continue growing."
"You are doing this for growth? Even at the cost of your life?"
"That is correct."
A person could risk their life merely for growth?
What is this child, that he is trying to become strong to this extent?
Haru looked at Yohan as if she had given up on him after what he had already done.
Even so, she absolutely had to resolve the question she had about him.
"Why do you have to become that strong?"
"That is...."
Yohan spoke with a face full of certainty.
"So I will not repeat the same mistake."