"These past three years, I've observed no less than 1,206 of your surgeries. Through meticulous records, I've come to understand precisely how much chakra each jutsu—each procedure—consumes. Down to the nerve, I know how much chakra it costs to connect even a single synapse.
"And with these eyes of mine, I can see chakra. If there's even a slight deviation, I can correct it instantly.
"Your first surgery consumed 15% of your chakra. The second one? 45%. I know you well, Uchiha Kin. You can't resist the temptation of nine million—just like you couldn't resist me."
Hyūga Sen stood haughtily before Uchiha Kin, his silver eyes glinting with triumph, as if savoring the moment his scheme bore fruit.
This—this elaborate masterpiece of planning and manipulation—had finally succeeded. And in this moment of victory, Sen couldn't resist the urge to gloat.
Especially in front of Uchiha Kin—someone just as cunning, ruthless, and cold-blooded as himself.
"You must've figured it out by now, haven't you?" Sen smirked as Kin's lips parted slightly. "That's right. Both of those surgeries were deliberately arranged for you.
"Each time, I calculated the chakra expenditure precisely. I needed you to retain just the right amount of chakra... enough for me to replace your eyes. And when the surgery was complete? You'd have nothing left to fight with.
"Neural manipulation... I'll admit, Kin, you're a genius. A real prodigy—if only you weren't so blind."
He chuckled coldly. "Compared to you, even Tsunade would look like a rookie... quite a pity, really."
"It is a pity."Uchiha Kin's voice rang out unexpectedly.
Fine strands of nerves spread across his neck, mending what should have been a fatal incision. New flesh had already begun to grow. Behind his surgical mask, his expression was unreadable—but the tone suggested sarcasm.
"Your blade couldn't even kill me."
"Your chakra—how is this possible?!"
"Humans see objects because light enters the eye. The Byakugan can perceive chakra and even look through matter because it has specialized chakra-sensitive cone cells embedded in the retina.
"But if the object's glow isn't distinct—or blends in with the surrounding energy—and your cone cells are only tuned to one type, you won't see anything.
"And those chakra-sensitive cones? That's exactly how they work.
"If I don't let you see it... how could you possibly perceive it?"
Uchiha Kin remained seated, staring up at Sen.
Suddenly, Hyūga Sen let out a horrific scream and collapsed, dead before he hit the ground.
All Kin had done... was sever the neural bridges Sen had constructed—restoring the original nerve paths.
Once his brain received the new signal, those hijacked nerves began to wither and decay in real-time.
And when the nerves broke down...
The Caged Bird Seal—cut off from its chakra supply—interpreted it as a hostile extraction, triggering its self-destruction protocol, detonating from within the deepest parts of Sen"s brain.
The tendrils of the Caged Bird Seal—like thorns—violently burrowed and spread through his neural tissue.
He died instantly.
Normally, this would have destroyed Sen's Byakugan, but Kin's earlier surgery had severed the eyes from the seal's influence, sparing them.
Kin stood up and removed his gloves. A shadowy substance extended from his hand, splitting into two clusters of black tendrils, reaching into Sen's eye sockets. The eyes, still tethered by nerves, were extracted—like jellyfish floating on threads.
The two Byakugan eyes were absorbed into Kin's body by those writhing shadows.
Then, he retrieved the two other Byakugan preserved in nutrient solution.
"Hyūga..."
He stared at Sen for a moment, as if weighing something. Then, his hand reached out once more. Sen's body was quickly enveloped by Kin's shadow, spreading inky-blue patterns across his skin.
These markings, dense and intricate, flowed along Kin's arm—thick central roots branching into smaller tendrils—resembling wild grass roots.
If Sen had still been alive, he would've recognized this as the Nara Clan's Shadow Technique.
Except Kin's version wasn't Nara-like at all.
He wasn't mimicking. He wasn't restraining. He wasn't controlling.
He was assimilating—using shadows to merge Sen's nervous system with his own.
This is a common tactic in many ninjutsu-based teleportation techniques.
For example:
Water Release: Water Body Flicker
Earth Release: Headhunter Jutsu, Underground Fish Projection
These all follow the same principle. Among the three types of shunshin techniques—space-time, body-based, and ninjutsu-based—this is the most common.
(The other two being space-based like Flying Raijin, and body-based like Guy's instantaneous taijutsu bursts.)
Uchiha Kin looked down at Sen and sighed. "What a hassle."
Two went in. One came out. Explaining this would be... inconvenient. Still, he was certain Sen had accounted for this eventuality.
As Kin turned to leave, he glanced back at the corpse, a strange, inexplicable emotion rising within him.
This Caged Bird felt pitiful. And perhaps... more than a few Hyūga weren't bound by the strength of the cage, but by its value.
To escape the cage meant braving the world alone—giving up the prestige and protection of the Hyūga name. But staying inside... meant giving up freedom.
"The cage of the Caged Bird was built by the birds themselves," Kin murmured. "It wasn't strong to begin with—rather fragile, actually. All it needed was to be starved, and it would neither grow strong nor trigger its self-destruct function."
"To the Hyūga... it's simple."
"Stop using the Byakugan. Stop developing it. Then the seal can no longer siphon enough ocular power to be lethal. At most? It gives you a migraine.
"But only the hardworking branch members suffer its true wrath—because in training the Byakugan, they nourish the seal too. The more they hone their dojutsu, the stronger the cage becomes, until one day... it can kill."
Uchiha Kin smiled slightly at the thought.
As he exited the cavern, one of the four Byakugan implanted inside him activated.
The surrounding ten kilometers bloomed into vision—layered, chaotic, overwhelming. His first time using this sensory scope made him feel dizzy.
But his heart?
Elated.
"Fame and fortune… what are they, really?""Born with nothing, die with nothing…" he whispered, before vanishing into the forest.