Book of Seals

After bidding farewell to Hiruzen Sarutobi at the intersection, Nangō Kumoi walked alone along the road back to his residence.

The evening breeze was faintly cool, dispersing the warmth from the noodle shop and clearing his mind even further.

He had resolved a potential curse mark threat, settled on the direction of tomorrow's speech, and enjoyed a rather pleasant dinner with his senior brother. He was in a good mood, but not at all sleepy.

"It's still early when I get back. Why not... take a look at the 'homework' Sensei left behind."

He recalled that since taking office, aside from necessary administrative duties, he had indeed set aside a thorough review and improvement of his own ninjutsu system.

A breakthrough in strength needed to be consolidated, while one's horizons needed to be broadened even more.

Returning to his study, he dismissed the attendants and lit the lamp.

From a cabinet secured with multiple layers of seals, he took out the scroll that represented one of Konoha's highest-level ninjutsu secrets—the "Book of Seals (Copied and Annotated Edition)."

This was not the original. It was a copied volume Tobirama had specially prepared for him, containing summaries of the principles, training essentials, and danger warnings for certain core forbidden techniques and advanced ninjutsu. It also included some of Tobirama's own research notes and conjectures.

He unrolled the scroll, skipped over the techniques he had already mastered or did not need to study in depth for the time being, and fixed his gaze directly on several names that had long been famous and had left deep marks on the original timeline.

The first thing that caught his eye was [Multiple Shadow Clone Technique].

"Extreme chakra distribution and synchronized information feedback..."

Nangō Kumoi carefully read the explanation of its principles and Tobirama's annotations.

He knew better than anyone just how powerful and dangerous this technique was.

For someone like him, with immense chakra reserves and precise control, this technique was extremely practical.

Not only could it be used in battle to confuse enemies and surround them, but more importantly—it could greatly improve learning and work efficiency!

Don't ask why Kumoi had such immense chakra reserves. He had only recently learned that his body could store vast amounts of chakra. While he still could not match the Uzumaki's chakra reserves, he would certainly surpass them in the future.

As he thought of this, he began calculating inwardly:

If I can reliably create one or several Shadow Clones capable of independent thought, and have their experiences and fatigue feed back to the original body...

Then I could handle administrative duties, study scrolls, and even perform less strenuous ninjutsu training all at once... This is practically the ultimate time-management tool!

Still, the consumption of chakra and mental energy was indeed terrifying. He had to carefully control the number of clones and how long they remained active.

It could serve as a long-term training goal.

Next was [Flying Thunder God].

Seeing the technique's complex principles, its methods for marking spatial coordinates, its chakra instant-transfer formulas, and Tobirama's abundant notes full of attempts and corrections, Nangō Kumoi could not help but feel profound respect.

This was true Space-Time Ninjutsu, and its strategic value was immeasurable.

Whether for instant reinforcements, decapitation tactics, emergency evacuation, or supply deployment, it held revolutionary significance.

He began assessing it inwardly: its training difficulty was definitely SSS-rank.

It required extraordinarily sharp spatial perception, unimaginable chakra control precision, and reaction speed.

Although I've entered the Super Kage realm, I'm still completely inexperienced in this area.

However, with Ray's concepts regarding energy control and extreme speed to assist him—

Perhaps... I can find a unique point of entry into understanding the "anchoring" of spatial coordinates and the instantaneous burst of chakra "leaps"?

Even if he could not master it immediately, understanding its principles would be crucial for guarding against enemies who might possess similar Space-Time Ninjutsu in the future, such as that masked man.

He would place it on the list of deep research projects for now.

His fingers slowly moved downward, and the words on the scroll seemed to carry a chill.

[Dead Demon Consuming Seal]

This was an ultimate Sealing Jutsu that made one's spine go cold merely from reading its description.

At the cost of the caster's soul, it summoned the Reaper to devour the target's soul, perishing together with them.

It was the final trump card in a moment of desperation, as well as the cruelest choice.

Tobirama's annotation beside it was exceptionally brief, consisting of only one sentence: "Do not act rashly unless driven to the brink. Caution, utmost caution."

Nangō Kumoi remained silent for a long time.

He absolutely did not want the day to come when he would need to use this technique, but he had to understand its existence and its cost.

It reminded him that no matter how powerful he became in the future, some sacrifices would still be too heavy to bear. Every decision had to be made with the utmost caution.

Finally, his gaze settled upon a name that, though still incomplete, already exuded an ominous aura—[Impure World Reincarnation].

There were more records concerning this technique on the scroll than he had expected, but most were Tobirama's early theoretical deductions, experimental concepts, and records of several attempts.

Clearly, this was a technique into which his teacher had poured considerable effort, only to ultimately set aside and even seal away.

"Summon the souls of the dead, bind them to living sacrifices, and restore part of their power and consciousness..."

Nangō Kumoi read every word, his brow tightly furrowed.

He saw the terrifying military potential of this technique in theory—summoning powerful figures from history to fight for him.

But what truly alarmed him was the deep conflict and warning revealed in Tobirama's later notes:

"This technique touches the taboo of life and death, desecrates the peace of the deceased, distorts the natural order and morality, and may easily provoke uncontrollable backlash.

"For the sacrifices, it is even more cruel beyond measure.

"I have deduced it many times, and its controllability remains doubtful. Should the summoned possess too strong a will or too deep an obsession, there may be danger of backlash against the caster or even a complete loss of control.

"Furthermore, the abuse of this technique will inevitably open the door to an endless abyss of ethical ruin and tyranny of power.

"Unless it is a final measure forced by necessity for the sake of protection, it must never be used.

"Related materials must be sealed at the highest level. Future Hokage must exercise the utmost caution."

His heart churned like stormy seas. As expected! This was one of the roots of all the disasters in the original timeline!

Desecrating the dead, sacrificing the living, uncontrollable power, and a complete collapse of ethics... His teacher had seen every danger, which was why he had sealed it away.

It had to be strictly controlled!

Yet almost at the same time, a cold name surfaced from the depths of his mind—Madara Uchiha.

That "old schemer" lurking in the shadows, plotting the Eye of the Moon Plan, whose strength was unfathomable.

If he truly had to face that legend who had survived since the Warring States era in the future, how much chance would Konoha have with conventional power alone?

Impure World Reincarnation... Could this technique, which Tobirama regarded as taboo, become the only possible "unconventional deterrent" or desperate response capable of working against a monster of that level?

That thought filled him with a chill and a deep sense of conflict.

Both reason and emotion rejected the use of such an evil technique, but his sense of responsibility as Hokage forced him to consider every possibility.