Kimimaro was fascinated by the idea of growth in both spiritual, thanks to willpower growth, and physical energy realms, through the endless grind that extreme training could give him.
But genjutsu?
His lips curved faintly.
He couldn't see the appeal.
To him, it was the lowest-yielding road.
Ashina was right.
There was no "Eight Gates" of genjutsu, no way to push the boundaries beyond genius and bloodline.
As Ashina had hinted at, the pinnacle had always belonged to a single family: the Uchiha.
With their advanced Sharingan stages, they warped reality itself in overwhelming Yin power.
For everyone else, genjutsu was a trick, a stall, nearly a sideshow. Nothing more.
Yet Kimimaro wasn't foolish enough to abandon Yin Release entirely.
He had his suspicions.
'If Yin can be used to weave illusions into someone else's brain,' he mused internally, 'then it should be possible to weave protections into my own. A sort of… Yin Release: Inner Bastion. Constantly reinforcing and scrubbing my mind clear, layer after layer, so no foreign chakra can anchor illusions inside.'
It was only a theory, but a promising one.
He had the natural talent for Yin anyway.
His transmigrated soul, enlarged and sharpened, brimmed with spiritual energy.
It would be a waste not to leverage it in some way.
As for taijutsu, especially the Eight Gates, it was obvious where his focus would lie.
It was perfect for him.
His body was already a weapon.
Every bone sharpened into the sharpest blade.
Combine that with the raw speed and power of the Gates, and he could crush enemies before they even registered movement.
Pulverize them in the instant before retreat or defense.
In that scenario, ninjutsu was little more than decoration.
But Kimimaro wasn't blind.
He knew the truth: opening the Gates was an arduous process, a mountain no one climbed overnight.
Even with his willpower, even with chakra healing every strain, his body was still young.
There were limits to what flesh could withstand before maturity.
So, his path was clear.
Yin Release for defense and subtle growth.
Taijutsu and the Gates for overwhelming offense, perfectly married to his Dead Bone Pulse.
Ninjutsu for utility and versatility.
...
"What about the Eight Gates? What are they, how are they connected to taijutsu precisely, and how do I claim them fastest?"
Kimimaro eventually asked, after his daze, his tone casual, though his eyes sharpened.
Ashina gave him a long look, faintly surprised that a boy his age even knew the name.
Still, he answered without hesitation.
"The Eight Gates themselves aren't mystical barriers. They're simply names we gave to the natural limiters of the chakra pathway system. You know the tenketsu, three hundred and sixty-one tiny nodes scattered across the body, through which chakra flows. Each of those nodes can open, close, and regulate flow. The Eight Gates are like larger, central regulators along the main pathways: brain, lungs, stomach, spine, legs, arms, and so on. They keep your body from tearing itself apart under the weight of its own chakra and physical strain."
He paused, his tone heavier now.
"Open a gate, and you override that natural limit. Chakra floods the coils, muscles strain beyond their natural tolerance, and your body burns brighter and faster than it should. That's why the first few gates feel like strength and speed. But by the later ones, you're shortening your own life with every heartbeat. Those final gates are only a theoretical, pure destruction. They exist to keep men from ever touching them. To open them willingly is to accept death. The risk is not worth the reward, as demonstrated since ancient times."
Kimimaro listened, his expression calm but intent.
Ashina then went deeper, as if reading his curiosity.
"So, there is no secret 'technique' for the Eight Gates. No scroll, no formula. They're not a jutsu. They're what you stumble upon naturally as your body hardens. The stronger your flesh, the sharper the mind–body connection, the sturdier your frame, the richer your micro-coils, the more strain you can unleash and endure. That's all. In my time, I could open a few of the earlier ones. Many elite jonin, or even ordinary jonin, manage to learn how to open one or two unconsciously in moments of desperation or some intense training. But past that? It's the unproven domain of madmen and fanatics."
Kimimaro's lips curved faintly at that.
"Madmen and fanatics..." He echoed, voice dry.
"I suppose the line between them and the strong is always thin."
Internally, though, his thoughts shifted.
He was a little surprised.
If even Ashina, patriarch of the Uzumaki, not only knew about them so well, but also could open some Gates, then why hadn't their clans cultivated it more?
Why hadn't the Senju or Uzumaki, both more researched and cultivated than the Kaguya clan, and also so gifted in the physical realm, ever dug deeper into that path?
Their Sage Body bloodlines were obviously, practically tailor-made for it.
Then the answer came to him just as quickly.
'Because they were human.'
Great clans or not, they had the same flaws as everyone else.
The Gates demanded discipline, endless grind, belief, patience, and willpower bordering on insanity.
Why would Senju or Uzumaki chase such an uncharted, brutal road when they could gain faster results through ninjutsu, fūinjutsu, or even medical arts?
The temptation of easier, safer, more certain power would always win for most.
So, ironically, the ones most suited for it were the ones least motivated to pursue it.
Because that same amazing, talented bloodline also gave them other avenues to explore, unlike Duy, Guy, and Lee had.
In truth, the Eight Gates' true heights probably weren't even known until that one moment burned into his past-life memory.
Might Guy, soaring into the sky against Madara.
That was probably the first time the shinobi world saw what the last Gate could do.
Even if the result was death, who wouldn't want to have that as a deterrent in their arsenal?
Kimimaro's grin widened ever so slightly.
He wouldn't make their mistakes.
He'd walk that so-called foolish path.
He'd grind his bones, sharpen his body, and tear open the Gates until the world itself had to kneel.
Taijutsu and the Gates weren't just an option; they were a pillar of his climb to the top of the food chain.
Although Kimimaro had already sharpened his willpower during the long months of isolation, hunger, and silence, he now realized it wasn't nearly enough.
If what Ashina's somewhat ignorant words suggested to him was true, then willpower wasn't just some abstract virtue in this world. It was a tangible limiter.
A gatekeeper.
The one thing that separated those who stayed insects from those who climbed high enough to graze the stars.
Power here wasn't only about bloodline, chakra reserves, or talent.
Those were tools.
Multipliers.
But without the will to keep stepping forward, without discipline, without grind, even the best lineage rotted into mediocrity.
His own clan was proof of that.
Kimimaro clenched his hand slowly, his gaze steady.
He had a decent Sage Body, yes.
He had transmigrator's knowledge, yes.
But if willpower was truly the rarest edge in this world, then he would tune it sharper than any bone he could draw from his flesh.
He would forge it until there wasn't a single limiter left in him.
After all, talent and blood gave you potential.
But willpower was what decided who stood at the top.