Sukuna was arrogant, and sly to the core.
Right after he stole Fushiguro Megumi's body in Jujutsu Kaisen, he took a hit from the technique [Jacob's Ladder] and immediately played the part of Megumi to lure the caster in.
He knew Kurusu Hana had feelings for Megumi.
It was a scheme calculated around exactly what would happen next.
So even if he were told everyone else had died, even if he were left alone, he was the kind of monster who would still search for a way to incarnate completely.
And he knew how to wait for the right moment.
After all, he was a master at spending vast stretches of time with his brain effectively switched off.
Even so, this encounter had shocked him.
For the first time in his life.
'Those things... had no Cursed Energy at all.'
Sukuna had observed all kinds of humans through Yuji's eyes as he watched the jujutsu world.
Special Grade Jujutsu Sorcerers.
There had even been sorcerers with techniques worth coveting.
He had seen Heavenly Restriction users born with absolutely no Cursed Energy.
But this was different.
The Servants, Kadoc included, had no Cursed Energy, yet they carried another form of power in its place.
And it was intense beyond measure.
Especially Kadoc. The amount of energy he possessed dwarfed Sukuna's own.
Even the word "overwhelming" felt pitifully inadequate.
Perfect. Boundless.
With a single glance, Sukuna had seen through it: Kadoc's energy was infinite.
He did not know it was Magical Energy, but he understood it was a power source.
Something eerily similar to Cursed Energy.
'And on top of that... those bastards are a problem too.'
Oni. Gods.
There had been things like them back in the Heian era, but not the real thing.
At best, they had been Cursed Spirits borrowing those forms.
That was all.
These, though, felt like beings ripped straight out of legend itself. Their very presence was different.
Everything about them was unfamiliar. Disorienting.
A tension he had not felt in a thousand years.
And inside that tension, Sukuna searched for a way to survive.
But then—
"Mm... I get that you're vicious, but there's no way you can beat those people. They're not human, exactly, but still."
That was the testimony of the insolent brat, Yuji.
And as if to prove it, there were four more vessels on top of the ones already present, each openly releasing enough pressure to crush the air.
Then there were three Special Grade Jujutsu Sorcerers who would be a pain to deal with even alone.
That made six.
He had never once felt disadvantaged just because the enemy outnumbered him...
But this time was an exception.
For the first time in his existence, Sukuna felt the suffocating frustration of standing before a wall.
The same wall all those humans he had killed—
And all those who had tried to kill him—must have seen.
To kill Sukuna, his soul had to be separated.
And Yuji's [Disassembler] could separate only the soul.
So if we just waited...
If we waited until he fully grasped [Disassembler], maybe that would be enough. But it was risky.
If he messed up the manipulation and split himself apart too—
If he cut the body instead of the soul, there would be no fixing it.
'Using it on himself is too dangerous.'
For Yuji to use [Disassembler] on himself would be self-harm. Practically suicide.
I wanted to avoid that if at all possible.
Unless there truly was no other way.
Unless we were pushed all the way to the brink, to the point of cursing the game and reaching for the power button.
I turned all of that over in my head while meditating.
Even with my thoughts tangled, the flow of Magical Energy remained calm.
My attribute was Void, and manipulating ether was absurdly easy.
The quantity I possessed was overflowing, too.
So I was learning how to use ether itself, training with it, studying as much as I could.
'A way to kill only Sukuna...'
Was there really nothing? Feasible or not, I wanted at least one clue.
Personality death. Extracting only the soul. Things like that.
It felt like something should be possible, but no concrete method came to mind.
Not whether I could personally pull it off, but an actual workable approach.
Or at least an example.
After thinking for so long, my head started to throb.
So I emptied my mind and lay down.
"Haaah..."
The moment I sprawled out on the floor, a sigh slipped out.
It wasn't an immediate danger, not yet, but that final step kept bothering me.
Just in case, we'd only fed Yuji ten fingers.
That was manageable.
If it was only ten, then even in the worst-case scenario where Itadori Yuji lost control of his body, Gojo Satoru could handle it.
This time, Gojo had received my gift and his skill had risen sharply.
Taking that into account, he could even cover a full twenty-finger Heian-era Sukuna.
As long as Megumi's body wasn't stolen, it would be a pure one-on-one.
Sukuna would try to force things through a Domain battle, but I'd already given all the advice I could there too.
Make the Domain as small as possible to increase its durability.
Alter the conditions inside and outside the barrier.
Things like that.
From the start, while Sukuna was still dormant, we had been building countermeasures based on the events of Jujutsu Kaisen.
Countermeasures, and power to back them up.
Unless someone just stood there and let him take their body, there was no way we should lose.
'Leap into the depths of your heart~.'
I sighed and hummed random songs under my breath.
They just came to me on their own.
Into the heart... leap into the heart?
The more I rolled the phrase around in my mind, the more it felt like something was about to surface.
So I grabbed onto it and kept pulling.
Until it came to me.
"Oh."
And then, at last, a memory surfaced—something I'd seen ages ago while watching a tiny streamer.
It took a while to load. It had been that long.
Fate had a lot of series, and Extra was one of them.
Its spinoff, Extra CCC, too.
The setting was the Moon Holy Grail War and all that.
Forget the Moon Cell for a second. The answer was in CCC's story.
Diving into the other person's inner world.
And defeating them through that.
Inside the Moon Cell...
So maybe it would be difficult outside a kind of virtual world, but not impossible.
And not just in the CCC game. There had been a similar story in that Grand Order collaboration event too.
'Why the hell am I only thinking of this now?'
Now that I had an answer, I almost felt deflated.
This was what happened when you spent your life walking around with an empty head.
"Foreigner. Are you outside?"
"Yes, Master."
Click. The moment I called out, Koyanskaya of Darkness—Foreigner—opened the door and stepped inside.
The sparkle in her eyes was a little overwhelming.
"I called because I wanted to talk. Can you spare me a little time?"
"Of course."
Smiling, Foreigner sat down beside me.
The instant she sat, she linked arms with me. It happened so fast I barely had time to blink.
'Nice as ever.'
I nodded as I looked at the soft weight pressing against my arm.
No question. Full marks.
"Do you remember when we went to SE.RA.PH in 2030? That Singularity."
"Ah. Of course. That's where we took down Sessyoin Kiara. It was honestly absurd when the Third Beast showed up there."
Sessyoin Kiara was one of the Beasts that had appeared in Grand Order.
At the same time, she was also a Servant you could summon as a playable character.
She'd even shown up in an alternate version—same person, different class.
Wasn't that when she first got a unique animation?
Either way, I was glad Foreigner remembered what happened when we took Kiara down.
That made this conversation much faster.
"Then do you remember how we dealt with the Sentinel there?"
"I do. We dove into its inner world and..."
Mid-sentence, Foreigner fell silent, her eyes flashing.
Had she already caught on?
"You're saying the method itself is what matters, aren't you?"
"Yeah. I was thinking maybe we could adapt it and kill only Sukuna."
"That's a good idea. If we twist the existing magecraft formula a little, I think it should be possible."
The moment I saw Foreigner nod, I felt a weight lift off my chest.
So it really was worth trying.
"Really?"
"Yes. The problem is that the technique we used back then was something granted by BB, or by that unusual environment... so we don't know the detailed mechanism behind it."
"Yeah. That's true."
I sighed and nodded.
My Bond level with Summer BB—an alternate version, not normal BB—had only reached 14.
It was annoying to come up one short.
"For now, work in that direction. It'll probably be really difficult, so you don't have to think you absolutely must succeed. It's not urgent."
"Understood. I think it will take quite a lot of time to devise."
Foreigner leaned in close, shooting me a sidelong glance.
Even her dissatisfied expression was cute.
Kiss. Since she was already close, I gave her a light kiss. Foreigner's eyes went wide.
She probably hadn't expected that.
"Sorry."
"If you're sorry, then you'll have to pay the price, won't you? You've stirred up a beast, so pay for it properly."
Grinning like a predator, Foreigner shoved at my shoulder and pushed me over.
One kiss, and that was all it took to start the engine.
Because of that, the bed creaked. And kept creaking.
There was sweat, too.
I'd grown much stronger than before, but the method and result of supplying Magical Energy remained exactly the same.
Maybe because I'd worked up a sweat and cleared my head, I felt incredibly refreshed afterward.
My body felt light.
So I spent my days as usual, taking things easy.
The Shibuya Incident, which should have exploded by now, never happened.
The Culling Game didn't happen either.
And the Shinjuku showdown between Gojo and Sukuna that should have come at the end of it all never came to pass.
The number of fingers Yuji had eaten stayed the same.
We didn't feed him any more.
I met Yuji from time to time, and that meant seeing Sukuna too, but I didn't provoke him anymore.
If I pushed too hard, there was no telling what he might do.
'Peaceful.'
There was still one unpleasant thorn lodged in the back of my mind, but overall, things were good.
Good enough that I could travel whenever I wanted.
So for the first time in a while, I decided to go on a trip with Toji's family.
Megumi included.
'There are seriously a lot of us now.'
In mid-November, we boarded a train bound for Osaka.
Toji, Sae, Tsumiki, and Megumi.
Me, six Servants, and even Zenin Maki and Zenin Mai.
It was a pretty massive group.
Toji's wife, Sae, and his adopted daughter, Tsumiki, knew about the jujutsu world now.
Maybe it would have been one thing when Toji only had one foot in it.
But once Megumi stepped into that world, telling them was the right thing to do.
It was supposed to be a hidden world from ordinary people, sure, but plenty of ordinary people knew anyway.
As family, they deserved to know.
They'd been worried a lot, but now they were much more at ease.
Megumi himself had grown much stronger too.
"I feel a little bad, honestly."
Sitting beside me, Megumi let out a sigh.
The Servants were seated with each other.
Maki, Mai, Tsumiki, and Sae were sitting together too.
And me, Megumi, and Toji had our own seats apart from them.
For comfort's sake.
I looked at Megumi and asked, "Toward the others?"
"Yeah. Things are stable now, more or less, but it's not like Cursed Spirits have disappeared. Even if things are looser, we still take missions."
"Then just buy them souvenirs. Treat them to food too."
"Guess that's what I should do, huh?"
"If you look after them like that, the disappointment won't sting as much. Just get each of them something they like."
Nobara liked shopping, so clothes or luxury goods would work.
Yuji? Whatever, probably.
There were plenty of women around me who could give advice on gifts for a girl.
Shopping for a guy could be done roughly.
Yuji wasn't exactly delicate or timid.
"Hey, boss. About Sukuna—couldn't that Mahito guy's technique do something? The key is that it only messes with the soul, right?"
Toji asked the question while drinking canned beer.
He liked alcohol, but because of Heavenly Restriction, he didn't get drunk at all.
"It's a good thought, but [Idle Transfiguration] doesn't work on Sukuna. From the moment he incarnated in Yuji's body, he gained an understanding of the soul. His resistance to techniques is high too."
"Guess that fits the King of Curses. Watching Servants all the time has seriously messed with my sense of power balance."
Toji snorted and took another swallow.
Then he smacked his lips, sounding a little disappointed.
"Yeah. It's a shame."
I felt the same way.
Sukuna's fingers were Cursed Objects, so they couldn't be destroyed by Heavenly Restriction or Magecraft.
A guarantee of safety through a Binding Vow.
It was closer to a law than a mere application of jujutsu.
For a similar reason, the Cursed Womb: Death Painting brothers couldn't be destroyed before incarnation either.
That was the kind of Binding Vow we were dealing with.
'In the end, diving in and cutting his throat really is the answer.'
You couldn't kill him with the dive from the CCC collaboration event as it was...
So we'd have to modify the formula until it could.
I would be the one watching over it.
The ones doing the real work were the Servants, and honestly, I felt bad about that.
Which was why I was making up for it with my body as best I could.
That was what I could do.
And today, too, I planned to make up for it with my body.
Thoroughly.