Kakuzu moved before the darkness had fully settled. He was out from behind the rock and crossing the open ground at a pace that did not suggest urgency so much as purpose, the particular efficiency of someone who had decided what needed to be done and was doing it.
Sasori produced a scroll from inside Hiruko, broke the seal, and the smoke cleared to reveal his real body dropping into the puppet's housing in one practiced motion. The whole sequence took perhaps two seconds.
Finn stayed where he was and watched.
Sasori turned to him with that unsettling puppet gaze a moment before he moved. "Your bloodline limit," he said, and the way he said it was not a question but the beginning of a calculation. His eyes had a quality Finn recognized: someone who had just been handed new raw material and was already thinking about what to do with it.
"Don't," Finn said.
"I was simply going to ask if you'd be amenable to a study arrangement at some future point," Sasori said pleasantly.
"The answer is no. Study your own bloodline limit."
"I don't have one."
"Then study Kakuzu's."
Sasori said nothing further, turned, and moved toward the battlefield. Hiruko's approach was what it always was: low to the ground, silent, closing the distance without appearing to rush.
Below, the engagement had reorganized itself around Uchiha Kagami as its fixed point. The gravity field and the Abyss of Darkness had done their work on everyone else: the Cloud and Konoha shinobi alike were down, pressed into the dark-stained earth, unable to generate enough leverage to break free. Kagami alone was still standing, one knee having touched the ground briefly before he pushed back up through the weight through sheer force of will. His three-magatama Sharingan was moving constantly, processing the battlefield, building the map of what was in front of him.
Three attackers. Some coordination between two of them, loose familiarity rather than trained unit cohesion. The third, the puppeteer, operating independently as he clearly always did. A gap between them that a sufficiently fast shinobi could exploit.
Finn released the gravity field and pulled back the Abyss. The decision was tactical: holding both simultaneously against a target of Kagami's tier while also managing everything else was an unnecessary drain, and Kagami was the only target that mattered right now. The other shinobi were already contained.
The moment the pressure lifted, Kagami exhaled once through his nose and reassessed. He had been expecting the technique to sustain longer. Its withdrawal was either a tactical choice or a limitation he could use. He filed both possibilities and kept moving.
He looked at the three of them. Rogue shinobi, clearly. No headbands, no village identification, no obvious organizational markings. Operating as a unit of convenience rather than a structured team. The older one with the stitched face and the red eyes had been here longest and had the most developed sense of what Kagami was doing. The puppet user was handling his own agenda and would be a secondary threat rather than a coordinated one. And the tall one, the one who had released that incomprehensible gravity technique from several hundred meters away without hand seals, was still watching from a distance rather than engaging directly.
Take out the stitched one. Take out the puppeteer. Force the third to react rather than control.
He moved.
The body-flicker brought him behind Kakuzu in a fraction of a second, the ninja sword already in motion for a strike toward the center of mass where most shinobi kept their hearts. Kakuzu's arm extended: not a dodge but a response, black threads of Earth Grudge Fear bursting outward from his body in a radius sweep that covered every angle simultaneously. The sword cut through the threads cleanly. Kakuzu's arm shortened back. The threads that had been severed kept moving on the ground, twitching, still technically active.
Hiruko's mouth opened. A dense spread of senbon needles crossed the space between puppet and target, angled to cover every position Kagami could reasonably occupy. Kakuzu was inside that coverage arc. Sasori did not adjust for this. Kakuzu's existence was Kakuzu's problem.
Kakuzu formed a seal and said quietly, "Earth Grudge: Blooming."
From below the surface, threads erupted upward like roots breaking through soil, wrapping around Kagami's feet and ankles, locking him in place. Kagami looked down at them, then at Kakuzu, then made his calculation: he was not going to break free before the senbon arrived. Breaking free was not the play.
He drove the ninja sword into Kakuzu's back.
The blade went in. Kakuzu's body registered the hit without the particular quality of a man who had been stabbed somewhere vital. He hadn't been. Kagami had not had reliable intelligence on where Kakuzu's actual hearts were distributed. The thrust landed in the wrong location and produced pain rather than consequence.
The senbon arrived a moment later. The threads around Kagami's feet had held him exposed, and Sasori had not wasted the positioning. When the spread landed, Kagami looked, from the back, like someone had decided to demonstrate the concept of saturation. The needles were purple-tipped. Contact with the skin was all the mechanism required.
"Done," Sasori said, from inside Hiruko.
Finn said, "Maybe not."
"You doubt my poison," Sasori said. His voice had an edge.
Finn didn't answer directly. He had heard Kagami mutter something under his breath in the moment before the needles landed. A name, or something like a name. A short phrase in the register of someone invoking a technique rather than describing one. It was in the same family as Amaterasu, as Tsukuyomi, as Kotoamatsukami: names drawn from mythology to describe abilities that operated at the boundary of what should be possible.
"There's a higher level of Sharingan," Finn said. "You've heard of the Mangekyō."
It was not, specifically, a question for Sasori. It was a statement delivered into the general space of the situation, covering the answer he expected to receive from a different direction.
"You know more about the Uchiha clan than most people outside of it," Uchiha Kagami said.
He had turned around.
He should not have been standing. He was carrying enough senbon to have killed two ordinary shinobi through skin contact alone, and Sasori's poison was not ordinary. But Hiruko exploded before anyone could follow the logic of why Kagami was upright: the puppet detonated from the outside in, the senbon needles that had been aimed at Kagami a moment before now erupting outward from Hiruko's body in the same pattern and density, as if they had been gathered mid-flight and redirected. There was no visible mechanism. No chakra string. No technique announcement. The needles simply reversed and the puppet absorbed them, and Sasori, safely inside, registered the explosion against Hiruko's frame rather than his regeneration core.
Kakuzu staggered.
Two of the needles had found the gap between the threads and reached skin. Not many. Enough to matter, if the poison was what it was.
Kagami looked at Finn.
The pattern in his eyes had changed. The three magatama were still visible as their component parts but they had merged into something more complex, a new configuration that looked assembled from pieces but felt singular. Darker. More layered. Two thin lines of blood traced down from the inner corners of both eyes, following the line of his cheekbones and dropping from his jaw.
He had not opened the Mangekyō before this fight. That much was clear from the blood, from the weight that the technique carried visibly in the set of his face. He had not needed to. He was using it now because the situation had required it, and using it cost him something each time.
The Eternal Mangekyō was theoretically achievable, but required something Kagami may or may not have been willing to pay. The blood suggested he was working with the standard version. The standard version was extraordinary and still had a ceiling.
"Two of you," Kagami said quietly, looking at Finn, "handled."
Finn's gaze had already moved.
He was not looking at Kagami's eyes directly. He was looking at the region of his face, at the peripheral shape of the pattern in his peripheral vision, registering the presence of the Mangekyō without giving it a clean line of sight to work with. He had zero experience with genjutsu from the inside, zero trained resistance, no framework for detecting the moment it engaged. He was not going to find out what Kagami's specific technique did by letting it run on him.
He kept his eyes slightly off-center and let Observation Haki carry the awareness that his direct vision was not providing.
The Mangekyō was real. It was active. And he was being cautious, which was exactly the correct response.
Caution, in this particular situation, was not cowardice. It was the only sensible posture for someone who had just confirmed, at close range, that the most dangerous thing in front of him was not the sword or the ninjutsu or the body speed.
It was the eyes.