"Remember, only use shadow clones."
Konohamaru nodded seriously, then formed the hand seals according to what Naruto just started teaching him.
In a way, Konohamaru finally broke free from his canonical timeline restrictions.
In the original story, he had to wait until the Shippuden era—when he was around twelve or thirteen and Naruto returned to Konoha—to finally learn the Shadow Clone Technique while training the Rasengan.
Now, Konohamaru not only learned the Shadow Clone Technique years ahead of schedule, he was also about to speed-run Sage Mode.
And at this point, a classic question arose.
But what did it cost?
Although that classic question was usually dramatic and overused, it fit the current situation perfectly.
In less than half an hour, Konohamaru was twitching in the dirt like a certain electric mouse.
True, Konohamaru strictly followed the rule of only applying Lightning Release to his shadow clones.
But the sensory memories transferred back by the popping clones still triggered his main body's conditioned reflexes, and there was no way to block that.
His shadow clones didn't disappear normally either.
Kakashi applied a method similar to "low-temperature slow cooking," starting from the weakest electrical current and slowly ramping up the voltage layer by layer.
They hadn't successfully triggered Sage Mode yet, but they successfully discovered the exact breaking point of Konohamaru's shadow clones.
After mapping that critical threshold, Kakashi kept the voltage hovering just below it, repeatedly shocking Konohamaru's clones until the kid ended up twitching on the ground.
"Kakashi-sensei... can't you just invent a specific Lightning Release jutsu for this?" Konohamaru asked weakly.
"Konohamaru, you need to understand something. Even if I develop a new jutsu, your chakra natures are Fire and Wind. You still wouldn't be able to learn it. If I stick to raw, basic lightning chakra stimulation, you can at least find another shinobi nearby to shock you. But if I engineer a brand new, highly complex jutsu, then random Lightning Release users won't be able to learn it on the fly to assist you," Kakashi explained, frowning.
It wasn't that Kakashi didn't want to develop one.
The requirement were just a nightmare.
Even if he engineered the perfect Lightning Release technique, Konohamaru couldn't learn it himself, and standard Lightning users couldn't instantly master it to help him trigger Sage Mode.
"Then... what about Fire Release and Wind Release? Grandpa told me before that Kakashi-sensei mastered all five chakra natures." Konohamaru tried a different angle, looking up from the dirt.
"I have. But putting aside the fact that I'm not exactly a grandmaster with Wind Release, the fundamental problem is that Fire and Wind possess vastly different properties from Lightning. Fire burns and Wind cuts. Neither of those elements can have their lethality scaled down in a way that triggers Naruto's... shortcut." Kakashi shook his head.
"So that's how it is..." Konohamaru collapsed onto the ground and closed his eyes.
While recovering from the phantom shocks, the kid started brainstorming a new method.
Meanwhile, Kakashi prepared to start his own training. Konohamaru's question sparked a realization.
Kakashi didn't actually need to use raw, untamed Lightning Release chakra.
He could entirely custom-tailor a brand new Lightning jutsu for his own personal use.
So Kakashi sank into deep thought.
Naruto swam around in the river for a while, then noticed the shore had suddenly gone quiet.
Startled, he thought Kakashi and Konohamaru might have fried themselves to death, and he hurriedly scrambled out of the water.
When he looked over, both of them were just sitting in the grass with their eyes closed, meditating.
Naruto immediately felt annoyed!
It was fine if he slacked off, but why were Konohamaru and Kakashi-sensei slacking off?
He was still waiting for those two to carry him and summarize the instruction manual!
"I've got it!"
"I've got it!"
Just as Naruto marched over to yell at them, both of them snapped their eyes open and shouted in unison, scaring the absolute crap out of the blond kid.
"G-Got what?!" Naruto stared at them blankly.
"I found a way! Naruto-niichan, wait here a bit! I'm going back to grab some gear!" Konohamaru jumped to his feet, explained excitedly, and sprinted back toward Konoha.
Naruto couldn't tell if Konohamaru actually figured out a method, or if the brat just invented an excuse to run away from the training.
So he shifted his gaze to Kakashi.
"Naruto, step back. I'm going to try engineering a new jutsu."
Kakashi grabbed his right wrist with his left hand, and highly concentrated Lightning Release chakra began crackling violently.
"Oh, okay!"
Naruto scrambled back, his eyes locked on Kakashi.
Whether Konohamaru ran away or not, Kakashi-sensei stayed.
As for engineering a new jutsu... Naruto needed to watch carefully and steal some notes.
Maybe he could invent some flashy new jutsu too.
After a while, Konohamaru returned, carrying a small bag of who-knew-what.
But the kid didn't immediately begin his own training. Instead, he joined Naruto in watching Kakashi's jutsu development.
This was the elite Copy Ninja of Konoha drafting a brand new jutsu from scratch right in front of them!
It was a once-in-a-lifetime masterclass.
Although Konohamaru had a theory, he wasn't exactly confident he could execute it.
He needed to absorb some experience from a senpai first.
As time passed, Kakashi no longer needed to grip his right wrist to manually choke the chakra flow.
He condensed the energy using only his right hand, and the blinding blue Lightning Release chakra gradually shifted into a deep, volatile purple.
In the original timeline, after Kakashi lost his Sharingan, he engineered Purple Electricity because he could no longer use the Chidori or Raikiri without suffering fatal tunnel vision.
Compared to Raikiri, Purple Electricity lacked the linear speed, but it served as a straight upgrade in every other category.
It utilized both advanced shape transformation and nature transformation.
It possessed higher destructive output and could even be unleashed as a massive, omnidirectional AoE attack.
The control was insanely precise. It didn't even require hand seals to cast.
Of course, the current Kakashi didn't stumble upon the inspiration the same way his canonical future self did.
Kakashi's inspiration came from a certain store he visited in his youth, which sold a strange silicone tool that delivered mild electrical stimulation.
The brand name was 'Purple Mood.'
On top of that, he factored in the core concept of the Rasengan—a jutsu that required no hand seals—invented by his teacher, Namikaze Minato.
And finally, there was pure, absolute necessity.
The jutsu had to allow hyper-precise control, with freely adjustable shape and voltage.
As for linear speed? Completely unnecessary.
After all, the primary purpose of this jutsu was not to assassinate enemy ninja.
So, although the process took a wildly degenerate detour, Kakashi still managed to invent Purple Electricity years ahead of schedule.
Since it offered flawless voltage control and shape manipulation, Purple Electricity could be spread into a wide-range net.
Kakashi didn't even need his shadow clones to cast the jutsu on themselves.
He only needed to cast it from his main body, aim the localized net at his clones, and let the perfectly calibrated electrical current stimulate them into triggering Sage Mode.
"Kakashi-sensei... is inventing a jutsu really that easy?!" Konohamaru stood completely dumbfounded.
So this was the terrifying genius Grandpa talked about?
Konohamaru's eyes narrowed with fierce determination.
He absolutely could not lose to an adult! He would invent a new jutsu too!
Fuelled by spite and the Will of Fire, Konohamaru reached into his bag and pulled out the gear he just stole from the village.
A lighter.... and a fresh pack of cigarettes.