Uchiha Feiyu lingered in the dark space for a while, then slowly withdrew his hand from the swirling black mist.
He wasn't going to offer it.
The more black mist he stored, the better things he could trade for. And this time, he was planning to use targeted sacrifice—the kind that burned through an enormous amount of Death Miasma all at once. Naturally, the more he saved up, the better.
Right now, he was more than capable of surviving on the battlefield as he was. Even if he exchanged for some powerful new inheritance, it wouldn't turn into real combat strength overnight.
Whatever he got—whether sword art, body cultivation, or sorcery—would require time to train.
Look at the Bixie Sword Style, for example.
Even someone at Hatake Sakumo's level had spent months studying just the move-set portion and still hadn't fully digested it, let alone completely integrated it into White Fang Kenjutsu. And that was one of the simpler inheritances.
Anything deeper or more profound would take even longer.
"Konoha rotates front-line assignments…" Feiyu mused. "After this battle, I'll have been on the front for about half a year. I can probably apply for a six-month leave."
"I'll do the sacrifice then."
He grinned slightly.
"In the meantime, I'll just kill more Suna shinobi and stockpile extra black mist."
Decision made, he stopped paying attention to the Demonic Compendium and shifted his focus to something much more basic:
Training.
—
Ordinarily, once a shinobi reached Feiyu's level, short-term improvement became extremely difficult.
To advance further, you usually had two options:
Train higher-tier techniques—like Sage Mode, Lightning Chakra Mode, or Flying Thunder God.
Or awaken new bloodline powers—evolving your Sharingan, or fusing different chakra natures into new bloodline limits like Wood Release or Magnet Release.
Polishing basics again at that point, hoping to find some grand epiphany in fundamentals?
Not impossible.
But it was the kind of path that took ten years or more before the results truly showed.
Feiyu, however, wasn't walking the usual road.
With hundreds of souls and the Warden of Wandering Souls system to possess and train through, his efficiency didn't just double—it multiplied.
Maybe not a full hundredfold.
But fifty or sixty times?
Easily.
A month of training for him now was equivalent to five or six years of grueling, methodical polish for an ordinary shinobi. That was long enough to see tectonic shifts.
It didn't look like he was learning many new jutsu.
But under the surface:
His chakra flow speed had noticeably quickened.
His nature and shape transformations were about 50% stronger.
His hand seal counts for the same techniques had dropped by half.
Everything had grown.
He had finally completed a full elite jōnin foundation.
And when you layered that on top of:
the ferocious White Fang Kenjutsu,
and that disgustingly effective invisible-speed assassin style,
then even without Warden of Wandering Souls, he was already a full-blown mowing machine—approaching quasi-Kage from a practical-combat perspective.
—
On the other side, Hatake Sakumo had also been busy.
Freed from battlefield duty—no longer needing to constantly overlay Feiyu for fights—he threw himself wholeheartedly into studying the Bixie Sword Style from that other world.
Even stripped of internal cultivation methods and castration requirement, the sword style itself, on paper, was only third- or fourth-rate.
But that was only at normal speeds.
Bixie Sword Style was a technique built for extreme speed. Once the user's speed broke a certain threshold, those odd angles and intricate, tricky movements allowed it to leap instantly into first-rate territory.
For Sakumo, it was a revelation.
This was his first exposure to a sword style that relied on complexity and continuous forms to exert power, rather than a handful of simple, streamlined cut-lines taken to their limit.
In the ninja world, kenjutsu was fundamentally simple.
At the end of the day, it was just a set of basic slash mechanics arranged and recombined. Even Sakumo's own White Fang style contained no particularly elegant forms—just "faster, harder, cleaner," with all excess motion shaved away and a few simple movements trained to the utmost.
Most of the destructive power came not from the sword forms, but from the chakra-based ninjutsu layered on top.
Sakumo had always half-believed he'd reached the ceiling of what "White Fang Kenjutsu" could be.
Then he saw Bixie.
Only then did he realize how much space there still was in pure sword form variation.
After more than a month of careful study and selective assimilation, Konoha's White Fang finally finished fusing Bixie's tricks into his own style.
White Fang Kenjutsu was reborn.
Its original qualities—cold, swift, overwhelming—remained. But threaded through it now were strands of something else:
Odd, twisted angles. Feints tangled within feints. A venomous, sinister rhythm.
The instant-kill aspect hadn't weakened in the slightest.
Yet even in prolonged exchanges, the new White Fang Kenjutsu could steadily crush other high-speed specialists of the same level.
Feiyu soon realized something else.
Sakumo's revised sword style meshed perfectly with his own despicable invisible-speed playstyle.
Already grim and ruthless, White Fang Kenjutsu—combined with stealth—now carried an even deeper sense of eerie, ghostlike terror.
It was so oppressive, so unpredictable, that its threat in invisible mode was arguably even greater than in full Lightning Chakra Mode.
Of course, each mode had its strengths.
Stealth mode focused on weirdness and unpredictability.
Lightning Chakra Mode focused on direct power and overwhelming speed.
Choosing which to use would depend entirely on the battlefield situation.
—
As Feiyu himself grew, so did Sakumo's effectiveness when possessing him.
Now, when White Fang overlaid Feiyu, he could finally exert 100% of his original strength.
In fact, thanks to the upgraded kenjutsu, the combined performance was slightly stronger than Sakumo's own prime.
That kind of progress gave Feiyu a whole new level of confidence.
With war looming, he felt none of the cautious apprehension he'd had at the beginning.
If anything, he was… excited.
The Great Ninja War was dangerous, yes.
But it was also an opportunity.
In peacetime, wiping out a single four-man team from a major village was a big deal.
In wartime?
He could kill four hundred shinobi on the battlefield and nobody would even frown—as long as they were the enemy.
—
Back at Konoha's forward camp, Orochimaru watched Feiyu walk into the command tent, and a subtle flicker of surprise passed through his eyes.
This brat… has gotten much stronger again.
And it's only been a month.
His aura.
His breathing.
His posture.
Everything about him had changed—refined, sharpened. It felt like he'd been forged in years of grueling training, not weeks.
The battlefield could temper a shinobi's strength, yes.
But that usually meant experience: better reflexes, sharper instincts, smoother execution of old techniques.
The foundation—the raw underpinnings of chakra control and form—didn't usually leap forward this quickly.
Yet with Feiyu, that was exactly what had happened.
"This month has treated you well, Feiyu-kun," Orochimaru said at last.
Feiyu grinned.
"Last-minute polishing is better than no polishing," he said lightly. "Since the war's about to explode, I figured I should cram a bit of emergency training in."
Orochimaru was deeply curious about Feiyu's growth rate.
But he also understood something very clearly:
Top-tier shinobi all had their secrets.
He himself had plenty.
No matter how strong his urge to dissect the mystery, this was not the time—or the version of himself—to start opening people up to find out how they worked.
At least, not yet.
The Orochimaru standing here—before the end of the Third Great Ninja War—hadn't completely transformed into a mad scientist.
He just… had the inclination.
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