Tokyo Jujutsu High, full name Tokyo Metropolitan Curse Technical College, is a school built in the suburbs.
As the official institution for exorcizing Cursed Spirits, Tokyo Jujutsu High covers a vast area and is divided into several different zones.
Leaving the faculty area where Masamichi Yaga was, Lynn and Satoru Gojo arrived at the western plaza.
"What do you want to learn?"
"Black Flash, Reverse Cursed Technique, Domain Expansion, and I also want to ask about Binding Vows."
"Oh my, you really aren't being polite at all."
Satoru Gojo scratched his head, thinking about a teaching plan.
Despite being a teacher at Tokyo Jujutsu High, Satoru Gojo wasn't very good at teaching.
It was like learning math; some people can see the solution at a glance, and those with sharp minds can even complete the calculations in their heads to get the answer.
Meanwhile, those who aren't as bright stare at the same problem for ages without a clue, finally resorting to looking up the answer only to realize it's simple—yet they still won't know how to do it the next time they see a similar problem.
Satoru Gojo belonged to the former category.
As the strongest of the current era in the Jujutsu World, hailed as the one who broke the balance between Jujutsu Sorcerers and Cursed Spirits, he was an exceptional genius who could learn anything in a short time.
When others asked him how he learned something, he'd think for a long time and could only reply that it was as easy as breathing—just try it a few times and you'll get it.
Of course, such a method definitely couldn't be used for a class.
"Black Flash, Reverse Cursed Technique, Domain Expansion... of these three, the easiest to teach is the Reverse Cursed Technique. Though, given your exceptional self-healing ability, do you really need it?"
"Super-speed Regeneration is an invincible path, but having Reverse Cursed Technique adds another option."
"What's that? Sounds pretty impressive."
"I mean, less talk, more teaching."
"Yes, yes, yes~ Starting the lesson now."
Satoru Gojo raised his hand, and a mass of blue-black Cursed Energy flickered in his palm, emitting a powerful pressure.
"First, before the actual teaching, I need to ask how deep your understanding of Cursed Energy is."
"Anger, jealousy, hatred... the power extracted by controlling these emotions is Cursed Energy."
"Not bad, a very standard answer."
Satoru Gojo nodded: "As you know, Cursed Energy is a negative energy. Normally, it can only be used to strengthen the body but cannot heal it."
"The Reverse Cursed Technique is actually a multiplicative application of Cursed Energy. By multiplying negative by negative to get a positive, the negative energy of Cursed Energy is turned into positive energy."
As he spoke, a new stream of Cursed Energy emerged within the energy in Gojo's palm. The two collided and merged, turning the original blue-black Cursed Energy into a mass of azure energy.
"Simply put, that's how it works. So, Lynn, do you get it? It's fine if you don't; after all, even a genius like me only figured it out between life and death..."
"I get it."
Lynn's voice suddenly rang out.
Satoru Gojo was a bit surprised: "Really? Don't just talk big and mess up; if you fail the operation of Reverse Cursed Technique, it can cause Cursed Energy to run wild."
"I know. Since Reverse Cursed Technique requires merging Cursed Energy to produce new properties, it demands very precise control."
Lynn crossed his arms, closing his eyes to recall the details of the Reverse Cursed Technique that Satoru Gojo had just demonstrated.
This kind of thing wasn't difficult for him.
As more and more Lynns arrived in the Mist Space, the effect of 'becoming one' was gradually manifesting.
Aside from the most basic sharing of power, the Lynns had discovered another hidden trait: shared comprehension.
The first one to discover this was Prince of Tennis Lynn.
After finishing the National Tournament and heading to the U-17, he found that his learning ability had improved by leaps and bounds.
After testing, he found he could learn anything with startling speed, almost gaining a photographic memory.
Relying on this power, he achieved a breakthrough and opened the three great doors beyond the State of Selflessness.
Among the three doors of the State of Selflessness, the Pinnacle of Brilliant Talent had a powerful strengthening effect on brain capacity.
With the combined boost of shared comprehension and the Pinnacle of Brilliant Talent, current Lynn could memorize the content of anything he looked at with just a thought.
Like a camera, his eyes recorded the process of Satoru Gojo demonstrating the Reverse Cursed Technique in his mind and replayed it at an extremely fast speed.
At the same time, Satoru Gojo's explanation echoed in his mind. The details that the other had intentionally slowed down during the demonstration were now further magnified and clearly presented before Lynn.
"Make the Cursed Energy fluctuate constantly, and then bring two different fluctuations of Cursed Energy into contact."
Under Satoru Gojo's gaze, Lynn stood silently with his eyes closed for a few minutes. Suddenly, he raised both hands, a mass of Cursed Energy appearing in each palm, which he slowly brought together under his control.
The two masses of Cursed Energy gradually merged into one, and after a few seconds, changed from deep blue to light blue...
Bang—!
A dull sound echoed. After a small, unnoticeable error, the two halfway-merged streams of Cursed Energy suddenly exploded, creating a shockwave that recoiled onto Lynn.
"Pity, I failed."
A look of regret appeared on Lynn's face: "I thought I could succeed in one go. It seems there's still some difficulty."
"Yeah, what a pity."
Satoru Gojo nodded, feigning composure: "You were just one step away from clearing it in one go. By the way, is this really your first time learning the Reverse Cursed Technique?"
"Of course, I have no reason to lie to you about this."
Lynn stood there and tried a few more times.
With the experience of failure, he had a deeper understanding of the multiplicative application of Cursed Energy.
At a deliberately slowed pace, he quickly completed the multiplication of Cursed Energy and activated the Reverse Cursed Technique.
"Done. Next one."
Lynn dispersed the azure energy in his palm.
"Are we teaching Black Flash or Domain Expansion next?"
"Black Flash can't be taught. I can only tell you some methods to train your Cursed Energy, and the rest is just lots of practice."
Black Flash is essentially the superposition of a physical attack and an energy attack. When the error between the physical strike and the Cursed Energy impact is within 0.000001 seconds, a spatial distortion occurs between the two, increasing the power to the 2.5th power of its normal state.
In this world where everyone loves to throw punches and use elbows regardless of their technique, the strength of Black Flash needs no explanation; it can be called the strongest elbow strike technique.
Furthermore, those who have performed a Black Flash will have a sensitivity to Cursed Energy far beyond before, manifesting as a significant increase in the precision of Cursed Energy manipulation and enhanced combat capability.
If there were a way to systematize Black Flash, the strength of the entire Jujutsu World would increase dramatically, and the casualty rate would plummet.
But unfortunately, the conditions for performing a Black Flash are too demanding. No Jujutsu Sorcerer can perform it at will, not even Satoru Gojo.
All he could teach Lynn were some methods to exercise Cursed Energy, allowing him to improve his control as much as possible and narrow the gap between the physical strike and the Cursed Energy impact. As for whether he could ultimately land a Black Flash, that depended on Lynn himself.
But unfortunately, the conditions for unleashing a Black Flash are too harsh; no Jujutsu Sorcerer can actively perform it, and Gojo-Sensei is no exception.
What he could teach Lynn were merely some spiritual methods for training cursed energy, allowing him to improve his control over cursed energy as much as possible and minimize the margin of error between physical strikes and the impact of cursed energy. As for whether he could ultimately succeed in landing a Black Flash, that depended on Lynn himself.
"The last thing is Domain Expansion."
After telling Lynn all the basic training methods, as well as the advanced training methods only accessible to Jujutsu High leadership, Gojo-Sensei's instruction entered its final phase.
"The essence of Domain Expansion is consuming a large amount of cursed energy to merge the Innate Domain and the Cursed Technique, manifesting it in the outside world. By the way, what is an Innate Domain? Do I need to explain it?"
"No need."
"That's good. Continuing our previous topic. To learn Domain Expansion, you need to meet three requirements."
Gojo-Sensei raised three fingers: "One, sufficient cursed energy. Two, a sufficiently high level of attainment in Barrier Techniques. Three, a sufficiently high level of understanding and development of yourself and your Cursed Technique."
"The first point is the easiest to understand. Domain Expansion is like a finishing move; under normal circumstances, casting it once can drain a Jujutsu Sorcerer's cursed energy entirely."
"The third point is also easy to grasp. Domain Expansion is a deep development of the Cursed Technique. If your understanding of your Cursed Technique is insufficient, you won't be able to merge it with your Innate Domain."
"As for the second point, knowledge of Barrier Techniques is the most crucial part of Domain Expansion. Whether it's manifesting the Innate Domain or merging the Cursed Technique with the Innate Domain, the process requires knowledge of Barrier Techniques."
Saying this, Gojo paused for a few seconds, giving Lynn some time to process. Then he continued, "Lynn, what is your attainment level in Barrier Techniques?"
Lynn: "Zero."
"Then you should focus on learning knowledge related to Barrier Techniques next. Let me think where to start... Got it!"
Gojo-Sensei, like an eagle returning from a long hunt, flashed and disappeared from his spot. When he returned three times, he was carrying a huge stack of books.
"I just borrowed these from the library of the Jujutsu world's higher-ups. They record all sorts of knowledge about Barrier Techniques, starting from zero. Once you learn all of this, you can graduate."
"Thanks."
Lynn took the books: "By the way, if the matter of stealing books is exposed, I won't be implicated, right?"
Gojo-Sensei waved his hand: "I said I borrowed them. How can you call what a scholar does stealing?"
"Besides, honestly, those old guys collect all these books but don't even read them themselves; they just hoard them to lock away knowledge from ordinary people. We can just return them later."
Lynn continued with his previous question: "If this matter is exposed, will I be implicated?"
Gojo-Sensei gave a wry smile: "You weren't even afraid of consuming Sukuna's finger, so what's a little bit of this?"
In other words, he would be implicated.
Shaking his head and sighing about having chosen his company poorly, Lynn packed up the stack of limited-edition books.
He had learned the Reverse Cursed Technique, and he had the methods for learning Black Flash and Domain Expansion. Coming to Jujutsu High this time had been extremely fruitful; it was not a wasted trip.
However, before class ended, he still needed to ask Gojo-Sensei about Binding Vows.
Gojo-Sensei: "Binding Vow? That's simple."
Compared to the previous topics, Binding Vow was considered basic knowledge, and the difficulty of learning it was not high.
"A Binding Vow centers on equivalent exchange. To strengthen a Cursed Technique, you must pay a certain price."
"The most basic Binding Vow is the Effect Introduction: by explaining the effects of your Cursed Technique before a fight, you can increase its power and gain an advantage in combat."
"Most people who use this type of Binding Vow are Jujutsu Sorcerers who prefer direct confrontation. Your Current Propulsion is very suitable for this type of Vow. Want to give it a try?"
"Sure."
Lynn nodded.
He still remembered what DanMachi Lynn had said a few days ago.
Don't set the initial Binding Vow too severely to avoid creating a chain reaction that screws over the other Lynns.
To avoid ending up like a certain blue-haired comedic girl who ruins herself in one move, the Effect Introduction was clearly a good choice.
Following Gojo-Sensei's guidance, Lynn quickly established the Binding Vow and tested it in a mock battle with Gojo-Sensei.
The overall effect was quite good.
After introducing the effect of Current Propulsion, the power and range of the lightning increased by 5%.
It didn't seem like much, but in a fight of equal footing, this 5% boost could very well determine the outcome.
"Thanks, Gojo-Sensei."
"Oh my, no need to be so polite. Honestly, teaching you was quite easy; it basically didn't require me to use my brain."
Gojo-Sensei looked completely relaxed.
What he said was the truth.
He had seen many genius students, the most typical example being Yuta Okkotsu from last year, who learned everything quickly.
But compared to Lynn's learning speed, even Yuta Okkotsu would have to admit defeat.
If it were another teacher, instructing such a genius student might lead to frustration, feeling like they, themselves were useless.
Gojo-Sensei was different; he loved to slack off.
Teaching a genius student like Lynn suited his tastes perfectly. If Lynn performed well later, he could even take the credit himself.
Perfect! This was the genius teacher, Gojo!
...The brief period of instruction came to an end.
It was now noon, and the diligent sun was working hard to transfer its heat to the ground.
Walking on the asphalt road hot enough to cook an egg, Lynn looked at Gojo-Sensei, who was leading the way beside him.
"By the way, have you set up any Binding Vows?"
"Nope, I don't need that kind of thing."
"I think it's better to set one up, otherwise you might be at a disadvantage when fighting Sukuna later."
"Sukuna?" Gojo-Sensei paused: "Come to think of it, you fought Sukuna once in the mental world. Did he set up any special Binding Vows?"
Lynn replied: "He used to allow people free entry and exit to his domain as a Binding Vow in exchange for a larger attack range. I thought about it carefully, and this Binding Vow seems quite suitable for you too."
Compared to Sukuna's Malevolent Shrine, Gojo-Sensei's Unlimited Void was truly a guaranteed hit; the moment an enemy made contact, their brain would crash, instantly killing even Special Grade Cursed Spirits.
"Want to try it? Converting your domain into an Open Barrier Domain through a Binding Vow."
"An Open Barrier Domain... Honestly, it's quite tempting, but I'll think about it later."
Gojo-Sensei did not accept the suggestion.
Although Unlimited Void was powerful, it had a drawback: it didn't distinguish between friend or foe.
If he unleashed an Open Barrier Domain in a crowd, the enemies would be instantly killed, but so would the innocent civilians nearby that he needed to protect.
Before encountering an enemy that required him to get serious, there was no need to turn his domain into an Open Barrier Domain; the current one was sufficient.