In a makeshift room, the students of Kyoto Jujutsu High sat listening to a lecture.
Ever since the entire dormitory and school building were caught up in the aftermath of Satoru Gojo's Hollow Technique a month ago, they had been studying in this temporary two-story building...
Kokichi Muta, acting as the lecturer, noticed that some of the students below were clearly not paying attention, so he knocked on the blackboard with his hand.
As for why he was not using a pointer or a book, it was because he had recently grown very fond of the feeling of directly touching things with his body.
Kokichi Muta held up a book so everyone could see the cover.
On it were the words: Fundamentals of Domain Studies, by Akira Zenin
"This book is a summary of the experiments Akira-sensei conducted during his time at Jujutsu High. He completed it before falling into slumber. Please turn to page two."
"As everyone knows, the Domain is the 'apex' of spellcasting. Many people see it as powerful, sacred, and immutable. But once you break it down, you discover that, under ideal conditions, the Domain is actually the most flexible ability.
Analysis of Domain Effects:
Guaranteed-hit:Guaranteed-hit EffectGuaranteed-hit Command Cursed Energy Conditions:Cursed Energy ConcentrationCursed Energy Environment
III. Isolation [Neutralization]:
Ritual Isolation [Neutralization]Conceptual Isolation [Neutralization]Physical Isolation
Conditions for Domain Expansion:
BarrierInnate DomainRitual
Under ideal circumstances, these conditions are not actually essential for Domain Expansion.
However, because the effects of these conditions are coupled together, omitting any of them is extremely difficult and is usually only done when there is no other choice.
The role of each condition is as follows:
Barrier [requires a certain level of Barrier knowledge]:
Main components:
Physical Isolation + Ritual Neutralization + Guaranteed-hit Command
Secondary component:
Cursed Energy Concentration
Innate Domain [requires self-exploration]:
Main components:
Cursed Energy Concentration + Cursed Energy Environment + Conceptual Neutralization
Secondary component:
Guaranteed-hit Effect
Ritual [requires possessing a Ritual and already beginning to explore the core of one's own Ritual]:
Main components:
Guaranteed-hit Effect + Ritual Neutralization
Secondary components:
Guaranteed-hit Command + Cursed Energy Environment
The actual effect of a Domain is formed through the interweaving of the main components of each condition and the mutual influence of their secondary components.
Conditions with the same main component can substitute for each other in that area. If one part is missing, that component will be weakened.
The coupling between secondary components is even stronger, but under extreme conditions, they can function as main components.
For example:
A Simple Domain, aside from the [Binding Vow], consists only of Barrier + Cursed Energy Manipulation.
Because it lacks the [Ritual Neutralization] provided by a Ritual, the [Ritual Neutralization] in the Barrier's main components either fails outright or is reduced to Ritual Dilution.
[Whether it fails or becomes diluted depends on the Barrier being used and the opponent's Ritual. In most cases, it fails.]
Its [Guaranteed-hit Command] can be used to offset the [Guaranteed-hit Command] of another Domain.
However, because it only has [Guaranteed-hit Command], it cannot use a Simple Domain to block a [Guaranteed-hit Effect] that has already taken effect.
A Simple Domain has [Guaranteed-hit Command] without [Guaranteed-hit Effect], so its [Guaranteed-hit Command] can only affect bodily movement through [Distortion]."
"Akira-sensei also expanded on these ideas in Domains and Correspondence Models.
He predicted more than thirty theoretical Domain models:
A Domain Extension that uses only Barrier and Innate Domain, with the Barrier focusing on the main component [Ritual Neutralization] and the Innate Domain focusing on the main component [Conceptual Neutralization].
Because Domain Extension uses only two components from two conditions, it is theoretically possible to carry out Domain Expansion at the same time...
He also predicted:
A [Mental Image Domain] that uses only Barrier and Innate Domain, focusing on [Guaranteed-hit Command] and [Cursed Energy Environment].
A [Field Mapping] that uses only Barrier and Ritual, focusing on [Guaranteed-hit Command] and [Guaranteed-hit Effect].
An [Open Domain] that uses all three conditions, but emphasizes the Innate Domain's Cursed Energy Concentration and Guaranteed-hit Effect while weakening the Barrier's Physical Isolation.
And also..."
Just as Kokichi Muta was getting into it, he suddenly noticed the state of the students listening below. He was about to knock on the blackboard again, but then he saw Kasumi Miwa in the very front row nodding off, so he lightly tapped the lectern instead...
"Ahem. I've only just finished the preface..."
"Huh?"
Kasumi Miwa jolted awake.
Students who fall asleep in class always have an uncanny ability to tell when the teacher is talking to them.
Still half-asleep, Kasumi Miwa frantically flipped through the book in front of her, trying to find the word "preface."
But seeing her panic made Kokichi Muta panic a little too, and for a moment, he had no idea what to do next...
"Sigh... If Akira-sensei were here, you guys probably wouldn't be like this..."
"You've got that wrong..."
Mai, sitting to Kasumi Miwa's left, rolled her eyes.
"That's because Akira-sensei only teaches when you're out on missions... All he does is tell everyone to open the book, then he starts dozing off first..."
Slumped weakly over the desk on Kasumi Miwa's right, Momo Nishimiya spoke up.
"My head hurts... Isn't this supposed to be an elective... Wouldn't it be enough if people like Todo and Kamo just attended... Why does everyone have to sit through it together..."
Since this kind of newly introduced elective was usually taught with all grades together, third-years like Noritoshi Kamo and Aoi Todo were there as well, aside from the first-years who were out on missions.
"Because once you grasp the method, some of the things in here are within reach for a lot of people..."
That voice from the doorway made everyone in the classroom turn to look.
"Back in ancient times, Domains were not nearly as rare as they are now. What people used back then was closer to the [Mental Image Domain] described in the book.
The requirements for understanding Rituals and for the amount of Cursed Energy were not nearly as high...
I have very high expectations for you... for everyone..."
"Akira-sensei!!"
Akira Zenin smiled with narrowed eyes.
"Good morning, everyone. It's dreamwalking time~~"