By the third time he sprinted up the cliff, Sasuke's lungs felt like someone had swapped them for hot gravel.
The rock face of Training Ground Three reared up in front of him, pale in the late afternoon light. He hit it at a run, chakra slamming into the soles of his feet, carrying him vertical. Dust trickled past his face. His calves burned. Halfway up, his footing slipped a fraction; he overcorrected, chakra spiking too hard, and the world lurched sideways.
He slammed shoulder-first into the rock, then slid ignominiously back down to the grass.
"Again," Kakashi said mildly from somewhere behind him.
Sasuke pushed himself up with a hiss through his teeth. "I know."
He didn't look back at his teacher. He could feel Kakashi's gaze on him anyway—lazy on the surface, weighing and measuring underneath.
The prelims, the Forest, the sound of Lee's bones breaking under Gaara's sand—none of that had left his head. Every time he closed his eyes, the arena reappeared. Every time he opened them, there was the cliff.
Run faster. Hit harder. Don't fall behind.
Simple math.
He took off again.
Grass. Kick. Dirt. Then the jolt as the tree line vanished and the cliff face rose up like a wall, and his body did the conversion it was learning: horizontal to vertical, earth to stone, chakra-negotiated gravity deal.
The Sharingan wasn't open. Not yet. This was just him and the rock and the screaming muscles.
By the time he dropped back down again, this time on his feet instead of his side, sweat had soaked the collar of his shirt. His neck itched where the curse seal sat hidden, a constant tiny burn, like a brand that never quite cooled.
Kakashi's hands were in his pockets. He hadn't moved from his lazy lean against a boulder.
"You're pushing your chakra too much into your toes," the jōnin said. "Spread it more evenly along the sole. Unless you're planning to fight only with your big toe, in which case, by all means."
Sasuke wiped his forearm across his jaw. "You could demonstrate instead of narrating."
"Ah, but demonstration is later," Kakashi said. "Right now, this is speed training. If you can't hit the acceleration window, what comes next just makes a very impressive crater and one very dead Uchiha."
Sasuke's jaw tightened. "I can hit it."
"You will," Kakashi corrected. "Eventually. Again."
So he did it again.
And again.
Somewhere around the eighth run, he gave up on counting and leaned into the rhythm. Ground. Kick. Wall. Run. Drop. The repetition burned a groove through the fogginess in his head.
His body remembered things he hadn't decided to remember.
Lee's ridiculous green form flashing around him that day on the academy balcony. The humiliated shock of hitting stone he never saw coming. The way Lee's weight shifted right before he disappeared; the odd little toe-first push that started every burst of speed.
His muscles stole it. Filched little adjustments from those memories; a lower center of gravity here, a tighter rotation of hips there.
Kakashi's own corrections layered on top—turn your foot like this, don't waste that movement, straighten your spine, you're cutting your own momentum.
The Sharingan flicked on of its own accord on one run, red tomoe spinning life into the world. For a heartbeat, he saw his own body in ghost doubles, the next step already traced ahead of him, the optimal path up the wall outlined in soft light.
He realigned.
It felt like someone had carved a channel into his nervous system. All he had to do was pour chakra into it and his feet landed where they were supposed to.
When he hit the top this time and launched himself off, the air gave way cleanly. He dropped, rolled when he landed, and came up on one knee instead of his back.
Kakashi gave a single slow clap.
"Better," he said. "Beginning to resemble a shinobi."
Sasuke stood, panting. "You said there was a technique."
"Impatient," Kakashi said. "Must be Tuesday."
He pushed off the boulder and strolled forward, the picture of casual. The wind tugged at his silver hair; his hitai-ate was tilted like always, hiding that eye Sasuke still hadn't seen.
Kakashi stopped a few meters in front of him and held up his right hand.
"Watch closely," he said. "And don't move."
Sasuke's stomach flipped at the tone. He watched.
Kakashi's visible eye narrowed. Chakra flooded to his hand—not in a smooth, gentle flow, but forced. Compressed. Sasuke could feel it, even without touching his own chakra sense, like the pressure before a storm.
Then the sound started.
At first, it was like insects. A faint, high chit-chit. Then it grew, multiplied, layered over itself until the air around Kakashi's hand screamed. Lightning crawled along his fingers, blue-white and hungry, stabbing out in little arcs that clawed at the grass.
The sound of a thousand birds, all shrieking at once.
The hair on Sasuke's arms stood up. The skin of his teeth ached.
Kakashi's hand was no longer just a hand. It was a knife made of thunder.
"This," he said, voice raised over the noise, "is Chidori."
He didn't give a lecture. He simply moved.
One instant he was there. The next, he blurred forward—body low, feet tearing up earth, that shrieking mass of chakra at the spearpoint. The ground under his path scarred, a shallow gouge cut by the sheer pressure.
He hit the cliff wall.
Stone exploded. Dust geysered. When it cleared, there was a hole punched clean through the rock big enough for a person to crawl through, edges fused and blackened.
Kakashi stood with his palm buried to the wrist in the stone, shoulders relaxed, as if he'd just knocked on a door.
The Chidori's sound died in an instant, cut off. The sudden silence left Sasuke's ears ringing.
Kakashi pulled his hand free and shook it once, flexing his fingers. His palm was red, skin blistered in places. He didn't seem to care.
Sasuke stared.
That.
That was the kind of power that didn't care about sand shields. Or genius exams. Or cursed marks.
He wanted it so badly his teeth hurt.
The first time it hit, I was three floors up in the hospital, squinting down at Lee's latest chakra map.
Migaki had drawn me a diagram earlier, all medical ink lines and grim little notes about ligaments. I'd been trying to match the physical damage to the way Lee's chakra pathways looked in my head—torn paper repaired too many times.
I was halfway through shading in a scar cluster when the world went sharp.
Chakra flared somewhere outside the hospital. Not close-close, but close enough. It lanced across my senses like someone had jammed a live wire into the side of my skull.
I sucked in a breath.
It wasn't like Gaara's—wrong and suffocating. It wasn't like Naruto's, wild and fox-bright. This was… narrow. Forced. A drill of blue-white static twisting tighter and tighter until it was "too sharp to be alive."
The sound followed an instant later, muffled by distance and walls: a faint, shrill keening that made my molars vibrate.
I clapped a hand over my ear, even though that did exactly nothing.
"What in the world…?" Iyashi murmured from the doorway, brow furrowing. He glanced toward the window, toward the training grounds, then shook his head. "Jōnin show-offs."
The flare vanished, cut off so abruptly it left a hollow.
I blinked spots out of my vision and forced my hand away from my ear. My pen had skidded across the page, leaving an ugly black streak where Lee's chakra pathways were supposed to be.
"Great," I muttered. "Now I get to add 'weaponized tinnitus' to the list."
Whatever that technique was, it didn't feel like something meant for patching people up.
It felt like something designed to put holes in the world.
Kakashi let him stare at the hole for a few seconds before breaking the silence.
"Cool, right?" he said, far too breezily.
"What was that?" Sasuke demanded. "Exactly. Not just the name."
"Lightning-natured chakra," Kakashi said. "Condensed and accelerated until it wants to punch its way through anything in front of it. The speed amplifies the force. The eye"—he tapped under his hitai-ate—"keeps you from running yourself headfirst into something you didn't intend to kill."
He looked at Sasuke, letting that sink in.
"This is not a scratch technique," he went on, tone shifting. "It is not for sparring. It is not for impressing academy brats. You aim this at someone when you are prepared for them to stop existing."
Sasuke's heart thudded at the bluntness. "So teach it to me."
Kakashi sighed like a man who'd hoped for at least a token show of hesitation and knew better.
"Step one," he said. "You still need more speed."
Sasuke glared.
"Step two," Kakashi continued, unbothered, "you learn to shape lightning to your hand without electrocuting yourself. Come on."
They moved to a clearer patch of ground, away from the cliff.
Kakashi demonstrated slower this time, letting Sasuke see the progression. Chakra gathering in the forearm, thickening, then funneling into the palm. The moment where it went from formless light to defined structure, the air around it warping.
"Think of it like… sculpting," Kakashi said. "You're compressing wind and lightning together into something with an edge. Too little and it just tingles. Too much and you fry your own nerves along with the target. Balance."
He nodded at Sasuke. "Your turn."
Sasuke stepped forward. Held out his right hand.
Lightning nature wasn't unfamiliar—he'd felt it in the crackle of certain training exercises, in the way Kakashi sometimes handled weapons. But doing it himself was different.
He pulled chakra up from his core, down his arm, into his palm.
For a moment, nothing happened.
Then faint sparks danced between his fingers, more static than storm. The air smelled faintly of singed cloth.
He pushed harder.
The sparks jumped, brightened, then flared too fast. A sharp bite shot up his arm, nerves screaming. His fingers spasmed open. The chakra collapsed.
He swore under his breath and shook his hand out, trying to get feeling back in it.
Kakashi watched with his head tipped to the side. "You're treating it like fire," he said. "Fire is volume and spread. Lightning is direction. Don't stuff it into your hand. Draw it there."
Sasuke gritted his teeth. "That makes no sense."
"Yes, well," Kakashi said. "Nature transformations rarely consult common sense."
They kept at it.
Time blurred into a series of small failures.
Sometimes there was no spark at all. Sometimes there was a burst of light and pain that shot past his wrist, leaving his arm buzzing like he'd slept on it wrong. Once, he overcompensated and the chakra blew outward, knocking dust and leaves back in a little unimpressive puff.
"Congratulations," Kakashi said dryly. "You've invented the world's worst leaf blower."
Sasuke rolled his eyes and tried again.
He dug into the memory grooves the Sharingan had carved for him. Lee's explosive acceleration. Kakashi's earlier demonstration. The way both of them moved with intent ahead of motion—already committed before their bodies followed.
He imagined the chakra lines in his arm as etched channels. Not a flood, but a wire. Not a bonfire, but a spear.
He pulled.
This time, the chakra came more cleanly. It flowed along the imagined lines, gathering in his palm in a small, tight knot. It tingled, then hissed. Tiny arcs jumped between his fingers, sharp and bright.
The sound was still faint, more a crackle than a scream, but it was there.
Electricity crawled up his bones. It hurt, but it was a good hurt, the kind that said something was happening.
He held it for three seconds before it sputtered out, leaving his hand numb.
"Better," Kakashi said. "Now do that a few thousand more times, and we can talk about moving while you hold it. And then, maybe, aiming."
Sasuke flexed his fingers. Feeling slowly crept back in, pins and needles stabbing at his skin.
"How did you come up with this?" he asked, unable to keep the curiosity out entirely.
Kakashi's gaze drifted past him, to the scarred cliff, to somewhere further.
"War," he said simply. "When you're young, fast, and still believe you can fix things by putting a hole in the right person, you invent a lot of ways to do it."
There was a weight under the flippancy that made Sasuke's chest feel tight and itchy.
Kakashi clapped his hands once. The sound snapped the mood.
"Anyway. Break," he said. "You're going to fry yourself if we keep pushing lightning through your nervous system without a pause."
He flopped down on the grass like a cat claiming a sunspot. Sasuke sat more stiffly, stretching his legs out in front of him. His breathing had finally evened out, but under the surface, his chakra felt raw.
The curse mark pulsed once at the base of his neck, an ugly, needy throb. The Five Elements Seal Kakashi had placed over it kept it from flaring, but it was still there. Waiting.
He ignored it.
For a while, the only sounds were leaves shifting and Kakashi's quiet rustle as he pulled out that stupid orange book.
"Sharingan," Kakashi said after a bit, as if they'd been in the middle of the conversation. "You're leaning on it more naturally now."
Sasuke frowned. "That's the point."
"Up to a point," Kakashi said. "The eye doesn't just show you what's there. The more you push it, the more it starts to… impose."
Sasuke glanced at him. "Impose?"
"Show you paths that don't exist yet," Kakashi said. He closed the book on one finger, not looking up. "If you're not careful, it'll start making real things that were better left in your head."
Something in his tone prickled the hairs on Sasuke's arms more than the lightning had.
"You mean genjutsu?" Sasuke asked.
Kakashi's visible eye crinkled. "Among other things," he said. "Let's just say I've seen more than one Uchiha lose track of where their thoughts ended and the world began."
He flipped a page lazily. "Don't chase that yet. Master not running into walls first."
Sasuke's jaw clenched. "I don't care about illusions. I don't care about hypothetical monsters in my head. I care about the power I can use now."
"Mm," Kakashi said. "And how do you think those hypothetical monsters become real ones?"
Sasuke turned away, irritation flaring hot.
"Let Sylvie play with her imagination," he snapped. "She's happy drawing everything in her head and talking about colors. I'm not." His fingers curled, remembering the incomplete crackle of chakra. "I just need enough power to crush what's in front of me."
Kakashi was quiet for a moment.
"Funny thing about 'enough,'" he said lightly. "It tends to move."
He let that hang, then slapped his hands on his knees and pushed himself up. "Alright. Time to see if you can run with the current on."
Sasuke stood too, blood humming. The ache in his muscles had settled into a familiar throb. The idea of channeling Chidori while moving made his nervous system wince in advance—and made something in his chest twist with anticipation.
They drilled until the light started to go.
Kakashi had him gather a small Chidori—just enough to spark and hiss—and then sprint a short distance, stopping before it blew up in his face. The first few attempts ended with him skidding in the dirt, hand jerking uselessly as the chakra fizzled.
By the fifth, he managed to keep it together long enough to slam it into a half-buried boulder.
The rock didn't explode. It cracked, spiderweb fractures racing out from the point of impact, a fist-sized chip breaking free and clattering away.
His arm screamed all the way to his shoulder. He had to bite down on a noise.
It still felt good.
"You're getting the shape," Kakashi said. "Good. Don't let it go to your head. Or do, and we'll see how fast I can knock you out before you impale yourself on a fence."
Sasuke shook his arm out, jaw tight. Sweat stung the corners of his eyes. The curse mark pulsed again under the seal, as if sulking at being left out.
The sharingan flickered, then faded. The world went back to normal color, edges blurrier, possibilities fewer.
He looked at the cracked rock, at the path cut through the dirt by Kakashi's earlier strike, at his own red, tingling hand.
Gaara's unmoving silhouette in the arena flashed behind his eyes. Neji's cold certainty. Orochimaru's tongue against his neck.
He would carve new grooves. In his nerves. In the ground. In the world.
Whatever it took.
The hideout smelled faintly of damp stone, cold metal, and medicinal herbs.
Kabuto knelt anyway, comfortable in the chill, hands folded neatly in his lap. His glasses caught the dim light of the underground lamps as he tilted his head, listening to the faint drip of water somewhere deeper in the tunnels.
"Your report," Orochimaru said from the throne-like chunk of rock he'd made his seat.
His voice slid along the stone like oil.
Kabuto adjusted his glasses with one fingertip. "As you suspected, Kakashi has begun training Sasuke privately," he said. "Lightning-nature technique. High-speed thrust. I was a safe distance away, but even from there, the chakra concentration was… impressive."
He chose that word deliberately.
Orochimaru's eyes half-lidded, amused. "Impressive enough to punch a hole through jōnin defenses?"
Kabuto allowed himself a small, knowing smile. "At Kakashi's level? Perhaps. At Sasuke's current one? No. Yet." He inclined his head. "But the foundations are there. The boy's nervous system is already adapting. Sharingan-assisted motor learning."
He did not mention the faint sting in his own fingers from where distant Chidori had made the air taste like metal. Orochimaru would hear it in the adjective.
"And the seal?" Orochimaru asked. "How does my little gift fare under the Copy Ninja's meddling?"
Kabuto lifted his shoulders in a half-shrug. "The Five Elements Seal is holding," he said. "For now." He echoed Kakashi's phrasing with mild satisfaction. "Sasuke's chakra flow is more stable, but the mark remains active at a low level. Like a… sleeping snake."
Orochimaru's smile sharpened. "Good. Let him think it's caged. A pet grows restless when it thinks the leash is all that binds it."
Kabuto dipped his head in acknowledgment.
He unrolled a second scroll.
"As for the village…" he said, "I've confirmed several useful details during my time in the hospital wards."
He let the list unfurl.
"Rock Lee. Post-surgery prognosis is guarded. The damage from the Gates is extensive; Konoha's medics are remarkably conservative with their estimates. Hyūga Hinata is stable but fragile. The hospital's night staff is competent but overworked. Security seals around the lower levels are… aging."
He flicked his gaze up briefly. Orochimaru was watching him with that snake-still attention, fingers steepled.
Kabuto decided to play his last card.
"And," he added softly, "the seal-brat we spoke of is now spending half her days in those wards."
A faint ripple passed through Orochimaru's chakra at that.
"Ah," he said. "The little pink-haired medic with the curious eyes."
Kabuto nodded. "Sylvie. No clan name listed. Unusual chakra perception. She described one jutsu as 'too sharp to be alive' without having seen it." He adjusted his glasses again, remembering the way she'd frowned at him in the infirmary, like she could see past his smile.
"She also has a knack for fūinjutsu," he went on. "The Hokage himself has taken an interest. Contract theory, containment seals. For now, it's basic containment and calming tags. But the talent is there."
He let a small, noncommittal hum escape him. "If Konoha survives long enough, she may become… interesting."
Orochimaru's tongue flicked out, brief, tasting the idea.
"Sasuke is the prize," he said, almost idly. "But it would be a shame to let a budding seal prodigy go entirely to waste. Tools are tools, whether they know whose hand they serve or not."
Kabuto smiled politely. "Shall I gather more detailed data on her as well?"
"Observe," Orochimaru said. "Don't touch. Yet." His eyes narrowed, pupils thin. "I want Konoha relaxed. Complacent. Let the children think their little month of training will save them."
Kabuto bowed his head.
"As you wish."
He rolled the scrolls up, tucking them away. On the margin of one, his earlier boredom had produced a small ink mouse, mid-scamper. As he stood, he brushed a fingertip over it.
The mouse twitched, shook itself, and skittered a few inches along the parchment before fading back into still ink.
A small, pleased curl touched his mouth at the motion.
"Busy hands, Kabuto," Orochimaru said lazily. "If you have time to doodle, you have time to scout."
Kabuto dipped in a deeper bow, hiding his smirk. "Of course, Orochimaru-sama."
He turned and walked out into the tunnel's dimness, footsteps soft on stone, already arranging his next few days in his head.
Lightning in the training grounds. Snakes in boys' veins. A seal-girl in a hospital full of cracks.
Konoha was very busy trying to make its children stronger.
Kabuto would be very busy making sure it didn't matter.