The sun had completely sunk below the horizon. Kenjaku stood alone on a mountain, watching the black sedan gradually disappear from view.
After Akira Zenin's Domain ended, there was no trace of Jogo anywhere. Yet Kenjaku showed no sign of surprise. She simply narrowed her eyes, quietly thinking.
[1. The range of his Cursed Energy detection is unexpectedly limited.
His technique development is extremely flexible. However, because his Cursed Energy output is too high and he deliberately restrains the power, using techniques causes damage to himself. There is a lack of smooth transition before activating techniques. There is roughly a half-second pause each time. His fatigue is more severe than the intelligence suggested. Even when extremely tired, he instinctively protects the people around him, and his protection toward students is even more thorough. Despite being a user of the [Ten Shadows Technique], he has not summoned a single Shikigami during this entire period, whether in battle or while traveling...]
"Finally got some information. But these are only surface observations. I'll need to sort out the internal logic once I get back...
Good thing Jogo warned those Cursed Spirits before taking action. Otherwise, going back now would probably mean dealing with those brainless idiots."
...
"Akira-sensei, during a Domain clash, if we deploy our own Domain to interfere with the Barrier, does that always cancel the opponent's guaranteed-hit technique?"
Megumi Fushiguro looked toward Akira Zenin, who was resting with his eyes closed. Akira sat casually, occupying most of the back seat by himself.
Tanabe, who was driving, twitched slightly at the corner of his mouth. The level of discussion happening inside this car was absurd. They were casually talking about Domains as if it were nothing.
"More or less~~ But in ancient times there was a technique that didn't use a Barrier at all. Instead, it directly projected the Innate Domain onto the surrounding environment.
In that situation, you can't enter a 'Domain push' state."
"Direct projection? So the world itself becomes the Barrier?"
"Who knows?"
"That sounds incredibly difficult... What happens if you run into something like that?"
"There aren't enough examples, so we can only speculate."
Akira Zenin forced his eyes open and sat up straight, resting his crossed hands on his knees.
"For now, let's call that technique an 'Open Domain'. Since an Open Domain has no outer shell, a Closed Domain cannot interfere with its Barrier.
And likewise, an Open Domain cannot disrupt the Barrier of a Closed Domain through 'pushing'."
"Then... does it become a race to see whose guaranteed hit activates faster and kills the other first?"
"Another possibility is that the guaranteed-hit commands cancel each other out. In other words, the overlapping area of the Domains loses the guaranteed-hit effect."
"Then doesn't that mean whoever has the larger Domain can directly attack the other?"
"Use that little brain of yours and think again."
Megumi Fushiguro fell silent, thinking deeply.
After a while, he suddenly raised his head.
"If the Closed Domain is larger, its guaranteed-hit effect still can't reach the center of the Open Domain.
But if the Open Domain is larger, it can directly attack the outer Barrier of the Closed Domain?"
Akira Zenin nodded.
"The logic is correct."
"Then wouldn't Open Domains have the advantage? Maybe even an absolute advantage..."
"If it's just an unexpected encounter, then yes."
Akira Zenin suddenly straightened up, his eyes becoming noticeably more lively.
"But having a disadvantage doesn't mean something is useless. Sometimes looking at a problem from the opposite direction gives you a completely different perspective~~"
"Opposite direction?"
Akira Zenin smiled, clearly intrigued by the topic. But instead of answering directly, he asked another question.
"Earlier I mentioned what happens when two people expand Domains at the same time. Let's talk about Closed Domains only."
"They enter 'Domain push', which causes both guaranteed-hit effects to disappear."
"Exactly. That means if you and your ally both expand Domains, they'll interfere with each other and cancel the guaranteed-hit effects. The result becomes one plus one being less than one.
That's why truly high-level battles between sorcerers are usually one-on-one."
Megumi Fushiguro nodded, showing he understood.
Akira Zenin couldn't help smiling again, clearly excited.
"The principle behind Domain push is the interaction between Barriers. So if you repeatedly experience how Barriers influence each other, then reverse-engineer a 'Double Barrier' that avoids that interference, and expand your Domain using it, you can eliminate friendly fire.
You might even be able to merge Domains."
Megumi Fushiguro's eyes widened.
"You mean that sorcerers who frequently use Closed Domains could learn 'Double Barrier' and achieve multi-versus-one combat in high-level battles.
But people who rely on Open Domains never experience 'Domain push', so they can't learn 'Double Barrier' and would be forced to fight alone.
And logically speaking, Open Domains can't eliminate friendly fire by modifying an outer Barrier into a 'Double Barrier'.
So a disadvantage becomes an advantage..."
"To be precise, in my eyes there's no such thing as advantages or disadvantages. It's only about how you look at the problem.
You still have a lot to learn, young man~~"
Megumi Fushiguro didn't argue. He simply nodded firmly.
Then something suddenly occurred to him.
"Then Akira-sensei... have you already figured out the 'Double Barrier'?"
Akira Zenin returned to his lazy posture, sprawling across the back seat even more than before.
He looked out the window at the trees sliding past.
"Well... who knows?"