Establishing Rules

The sea breeze blows from the east side of the deserted island, carrying a faint salty smell.

Uchiha Natsu sat cross-legged on the rock that he had used as a training platform for over a month, and slowly opened his eyes.

He raised his right hand, slowly closing his five fingers in front of his eyes, then slowly opening them again.

A very faint reddish-gold pattern remained on the skin's surface, slowly fading into the subcutaneous layer.

He could clearly feel the refined Natural Energy within his body—not as turbulent as Chakra, but more like a layer of warm water, gently permeating every inch of flesh, every meridian, and every cell.

Sage Mode, initially achieved.

He closed his eyes and then opened them again. The Three Tomoe in his pupils rotated once, and then a very faint dark golden halo appeared at the edge of the whites of his eyes, which disappeared in an instant.

It wasn't the menacing, battle-ready look of a celestial being, but something more restrained and profound.

He can now enter Sage Mode anytime, anywhere, without needing to meditate and accumulate power beforehand, or needing Shadow Clone to absorb Natural Energy elsewhere; all he needs is a single thought.

If this ability were placed in the Three Great Sage Lands — Mount Myoboku, Ryūchi Cave, and Shikkotsu Forest —it would already be the pinnacle of Sage Mode training.

But for the immortal Senjutsu inherited by the Void Demon Fox, this is merely the beginning.

The Sage Mode of the Three Great Sage Lands is essentially a combat enhancement.

By absorbing Natural Energy and fusing it with Chakra in a proportional manner, one can gain a comprehensive boost to combat power in a short period of time—greater strength, faster speed, and greater Ninjutsu power.

The drawbacks are also obvious: the duration is limited, and one needs to build up energy before entering. Once the balance between Chakra and Natural Energy is broken, one will be petrified at best, and die on the spot at worst.

The Void Demon Fox's Senjutsu was never designed for combat.

It can certainly be used for fighting. The Susanoo, empowered by Natural Energy, will be more robust than usual, its Fire Release will burn more intensely, and its Lightning Release will have greater penetrating power.

But these are all byproducts, incidental benefits on the path of cultivation, not the end point.

The ultimate goal is transformation—from a mortal to a higher form of life.

As a Guardian Spirit, Susanoo continuously absorbs Natural Energy from the outside world, refines it, and then feeds it back to its host through a soul link.

This process was extremely slow, so slow that Natsu's improvement in physical fitness was roughly equivalent to running for a few more days.

But it is continuous and never stops.

Refining a trace today, a trace tomorrow, accumulating day by day, over ten or twenty years, this body will be completely transformed under the nourishment of Natural Energy.

By then, his Chakra reserves will far exceed those of Hashirama Senju at his peak, his physical strength will be enough to withstand a full-force attack from Four Emperors, and the blinding curse of his Mangekyo Sharingan will be completely eradicated through the continuous evolution of his soul.

This is the true power of this Senjutsu —it doesn't make someone incredibly strong at a particular moment, but rather it elevates the entire Uchiha Clan to a species that transcends humanity.

He stood up and stretched his stiff neck.

The training is temporarily put on hold. After returning, I will first teach this Senjutsu to Fugaku, and then compile my insights from this period into a scroll. Anyone in the clan who can open Susanoo, whether it's with the Mangekyo Sharingan or the Three Tomoe, can learn it on their own once they get the scroll.

Then he needs to face a problem he doesn't really want to face but has to think about.

Bloodline.

The Uchiha Clan's bloodline is too special.

Sharingan, Susanoo, Sage Body, Sage Mode —all these powers are tied to the rope of bloodline.

If we allow our clansmen to freely intermarry with other clans, what if one of them has an accident during pregnancy and her bloodline is lost to others? If that bloodline were found and used against the Uchiha Clan, wouldn't that be almost the same as the Night of the Uchiha Massacre I remember?

The only difference might be that Uchiha Itachi was a complete Byakugan, someone you could never tame!

The safest method is, of course, endogamy within the entire clan. Thirteen thousand people are enough to maintain genetic diversity; that's how the Ninja World has survived for a thousand years.

Is it feasible?

Human hearts are made of flesh and blood.

To put it bluntly, even fairies descend to earth sometimes, let alone the Uchiha, who are not immortals but flesh-and-blood people who can cry, laugh, and feel emotions.

The Uchiha is a clan that loves deeply; the deeper their love, the more intense their hatred—the deeper the love, the easier it is for love to turn into hatred.

If one day in the future, a member of his tribe falls in love with someone outside the tribe, can he still hold a knife to their throat and forbid them from having feelings?

Instead of scrambling to fix things after they happen, it's better to establish the rules first.

Natsu paced back and forth on the rocks a few times, the sea breeze making his robes flutter.

After a moment, he stopped and mentally reviewed the thoughts he had just come up with.

First, women from other clans can marry into the Uchiha.

There's a system in place to back it up—the "Thriving Population" entry clearly states that the rate of bloodline thinning is reduced to zero, the probability of conception increases by 80%, and the mortality rate from Plague decreases by 60%.

The children born to the women he marries will still have pure Uchiha blood, their Sharingan will still be activated, and their Susanoo still be summoned; it won't affect anything.

Secondly, men from other clans who want to marry Uchiha women? They'll have to get past the threshold first.

Members of the Uchiha Clan's faction—note that these are not slaves, but free individuals—are only permitted to pursue Uchiha women after proving their potential, abilities, and loyalty, and receiving the approval of at least five Uchiha clan members.

Five people, not one person.

One person might be fooled, but with five pairs of Sharingan watching, it's not so easy to get away with it.

He thought for a moment, then added another rule to his mind: if Uchiha woman deliberately approaches him for personal gain or status, kill her in public.

He can't bear the shame.

Recalling the news I'd read in my past life, I remembered how some places set up a bunch of bizarre rules in order to prevent so-called "village assets from flowing out."

He certainly didn't want the Uchiha to become like that—but conversely, he didn't want the Uchiha bloodline to be diluted into an unsightly, common type after several generations.

Moreover, the origins of the Uchiha Clan are clear.

Their average strength is comparable to that of a naval lieutenant, and thanks to their ancestor Indra, there is almost no one in the clan who is not good-looking.

If you randomly pick someone who is strong enough to fight, good-looking, and a descendant of the Divine Tree —with such qualifications, is it unreasonable to require suitors to prove themselves first?

Compared to the Hyuga Clan's Caged Bird Curse Mark, he felt that his rules were already incredibly generous.

The members of the Hyuga Branch Family are controlled by Cursed Seal etched on their foreheads from birth to death. He neither shackled his clansmen nor restricted their freedom to fall in love; he simply added a few more bricks to the threshold.

If you're willing to step over it, then step over it; if you can't, don't blame the door for being too high.

He silently reviewed these points one last time in his mind, confirming there were no major flaws, then flicked his fingertips, and the light of the Flying Thunder God shone around him.

The sea breeze lifted his clothes one last time, and the next second, the reef was deserted, with only the waves still tirelessly crashing against the rocks.