Setsu began her report without hesitation.
Danzō listened with the same attention he gave anything that might matter later.
"The sequence proceeded as instructed," she said. "Once the forward operative moved against Fugaku Uchiha, I initiated the technique from concealment."
She had been positioned deeper inside the building, far enough from the corridor that Fugaku's team had no reason to suspect another operative was present.
Her chakra signature had been suppressed with a counter-sensory technique refined specifically for observation work.
That part had worked perfectly.
So had the opening of her own technique.
Danzō valued Setsu for many reasons, but that technique ranked high among them.
It had begun with ordinary Yamanaka principles.
The clan's traditional mental techniques projected consciousness directly into another target, powerful when successful, but burdened by obvious weaknesses.
Exposure. Vulnerability. Commitment.
A Yamanaka who sent too much of themselves into an enemy risked leaving their own body helpless or suffering badly if the connection was disrupted.
Setsu had spent years cutting away those weaknesses.
The result was something no other Yamanaka Danzō knew could reproduce.
She did not project her entire consciousness.
Instead, Setsu separated a controlled fragment of her spiritual power, wrapped it in chakra, compressed it, then expelled it toward a target as an independent spiritual intrusion.
A partial soul strike.
Small enough that her own consciousness remained anchored safely inside her body.
Dense enough to disturb another person's mind the moment it entered.
And, unlike the obvious mental projection of the clan's standard techniques, she had learned to suppress even the fragment's spiritual presence until the final instant.
The technique had eventually received a name.
Spirit Severing Art: Hollow Needle.
They were, in theory, detectable only by individuals with sufficiently good chakra perception.
And although they were incapable of outright possessing someone, they were designed to briefly disrupt consciousness, memory, chakra control, orientation, and mental resistance of their targets, making it a perfect supportive part of various "kill-nets" Root liked to employ.
By ordinary shinobi standards, it bordered on something stranger still.
Not quite ninjutsu.
Not quite genjutsu.
The closest thing Danzō had seen to a true "nin-genjutsu", spiritual interference given enough structure to be launched almost like a physical technique.
This was why Danzō considered it an entire combat principle rather than a single technique.
It did not need to be used as a hidden "assassination-like" tool like the Hollow Needle.
Setsu could apply the same principle openly in close combat, something already rare enough for a Yamanaka to border on unnatural.
By combining larger portions of spiritual power with chakra, she could shape more visible chakra constructs, sweeping beams, or traps, and heavier spiritual strikes without ever abandoning her own body.
Those versions were perhaps more taxing on her own being, easier to perceive and therefore easier to dodge, but that was the tradeoff for greater force and spiritual damage.
Not to mention that always, if it hit, it attacked the target's soul directly, bypassing normal genjutsu defense
More importantly, the principle was flexible.
Setsu had developed several techniques from it already, enough that it had effectively become a separate branch of combat rather than an isolated trick.
Danzō valued that greatly.
In fact, considering versatility, loyalty to procedure, experience, and raw usefulness, Mu might already be the single most valuable shinobi in Root.
There was, of course, no formal position resembling "second in command."
Danzō had no use for one.
Root had not even reached a hundred active members, and that suited him perfectly.
An organization like this benefited from remaining compact, compartmentalized, and personally controlled.
Too many layers created distance.
Distance created independence.
Danzō preferred knowing exactly who served beneath him and what they were doing.
Micromanagement, others might have called it.
He considered it discipline.
That innovation alone had justified much of the investment made in Setsu over the years.
...
"First, the technique entered cleanly."
Danzō gave a small nod.
That much was expected.
Setsu was already an "Elite-Jōnin" level of a shinobi, and in this particular application she had deliberately sacrificed force for concealment.
The Hollow Needle had been compressed to the point where detecting it before contact was far more difficult, even if that meant reducing the raw spiritual pressure behind the strike.
Against Fugaku, the priority had been getting inside cleanly.
Its purpose here had been simple.
Fugaku was to face two pressures at once.
The visible, weaker operative attacked physically from the front in full force.
"Mu" attacked spiritually from the shadows.
The taijutsu strike had never been the real test.
It existed to force movement, divide attention, and add another variable while Fugaku dealt with the more important interference from distance.
Her "attack" was what Danzō cared about most.
The Sharingan had long been known to interact unusually strongly with spiritual power through the brain pathway.
Tobirama Senju had spent years studying the Uchiha, their chakra, their emotional states, and the transformations in souls that likely accompanied the awakening and development of the Sharingan.
All of that "carefully left" research had helped Konoha's upper leadership understand that those eyes were not merely visual organs.
They reflected something deeper.
Chakra.
Mind.
Spiritual strength.
Perhaps even the soul itself.
So attacking that layer directly was useful.
If Fugaku's Sharingan possessed greater depth than reports suggested, the intrusion should provoke it.
If his spiritual defenses were unusually strong, they would resist.
If neither happened, that too was information.
And unlike a prolonged physical confrontation, spiritual pressure left considerably less evidence behind.
Fewer injuries.
Fewer witnesses capable of understanding what had happened.
More room for denial afterward.
It was a cleaner test.
Or it should have been.
Danzō had expected resistance.
Perhaps an immediate Sharingan activation.
Perhaps Fugaku would stagger, struggle to stabilize himself, then exchange several blows with the forward operative while fighting to keep his consciousness ordered.
If his response proved unusually strong, Mu would withdraw.
The operative in front of him had already been instructed how to de-escalate from there.
Yield a little ground.
Give Fugaku enough room to preserve face in front of his subordinates.
Allow both sides to step away without turning the incident into something more difficult.
That had been the intended range of outcomes.
Even a complete rejection of the "Hollow Needle" would have been valuable.
Particularly valuable.
Setsu paused.
Danzō noticed.
"Continue."
"Yes, sir."
Her voice remained flat.
"He did not... resist in the expected manner."
Danzō's eyes narrowed slightly.