The Surgical Test

Hokage Building, office.

The Third Hokage sat in his chair, watching Hatake Kakashi appear in the office, and smiled kindly. "Kakashi, you arrived quite quickly."

"When the Third Hokage issues an order, I dare not delay," Hatake Kakashi said respectfully.

The Third Hokage exchanged a few brief pleasantries before asking, "Kakashi, you have been in contact with that child Sasuke for two years now, haven't you? What do you think of his personality?"

Hatake Kakashi pondered for a moment, organizing his thoughts before saying, "He is calm, rational, and hardworking. He remains composed and collected in the face of adversity, occasionally offering sharp-tongued or thought-provoking remarks. Perhaps due to the events that have transpired in his life, he rarely expresses his emotions. Overall, he is a calm, diligent child who keeps his heart closed off."

The Third Hokage chuckled, teasing, "In that case, Sasuke is very similar to how you were in your youth, Kakashi."

Hatake Kakashi nodded in silence.

Through two years of contact, he had indeed discovered the shadow of his own youth within Sasuke.

Both had suffered a great tragedy, closed off their inner emotions, occasionally used sharp words, buried themselves in grueling training, and were single-mindedly focused on increasing their strength to prove something.

However, he had displayed more coldness back then.

Whereas that child displayed calmness!

Seeing Hatake Kakashi remain silent, the Third Hokage continued to ask, "Sasuke has been under your guidance for a year now, right? What do you think of his current strength?"

Hatake Kakashi spoke with a calm expression, "Sasuke is the most talented genius I have ever seen. At his age, my strength was not equal to his."

"It seems you hold that child in very high regard."

He was well aware that Hatake Kakashi had become a Jonin at the age of twelve. For him to give such an evaluation meant that Sasuke's strength had already reached the Jonin level.

Should one say, as expected of brothers?

The older brother's talent was outstanding, and the younger brother was not a bit inferior.

Thinking of the one who became a Chunin at 10, joined the Anbu at 11, became an Anbu squad leader at 13, and at 14...

The Third Hokage sighed inwardly, then said in a calm tone, "Sasuke is your student now, and his brother was also once under your command. In your opinion, how does Sasuke's current strength compare to Uchiha Itachi back then?"

Itachi?

Suddenly hearing the Third Hokage mention Uchiha Itachi, Hatake Kakashi's gaze darkened slightly.

He still did not know the truth behind the massacre of the Uchiha Clan.

He knew even less about the agreement reached between Uchiha Itachi and Konoha.

He also believed that the truth of the Uchiha massacre was as the rumors among the village Jonin suggested.

That Uchiha Itachi had committed extreme acts in pursuit of extreme power.

Although, even now, he could not understand why that seemingly calm and collected youth would do such a thing.

Hatake Kakashi was silent for a moment, then shook his head. "It is hard to say. Both Uchiha Itachi and Sasuke are ninjas proficient in ninjutsu, taijutsu, and genjutsu, with no obvious weaknesses. Sasuke has an advantage over the Itachi of that time in terms of taijutsu, physical fitness, and swordsmanship, but Itachi was stronger than Sasuke in genjutsu and practical combat experience. Plus, he also had the Sharingan..."

"It would barely be a draw."

Hatake Kakashi concluded with this final remark.

"It mainly depends on how much strength Sasuke can exert in a life-or-death struggle."

A life-or-death struggle is different from a daily sparring match.

Some people, when facing life-threatening danger and the fear of death, will erupt with power and potential far exceeding their usual limits.

Others will tremble in fear, unable to exert even half of their full strength.

The Third Hokage nodded, and after pondering in silence for a moment, a smile appeared on his face. He said gently, "I understand. You may go now, Kakashi. Oh, and don't forget about the Jonin promotion next month; remember to prepare for it."

"Yes, Third Hokage," Hatake Kakashi replied respectfully, turned, and left the office.

"Sigh..."

After Hatake Kakashi left, the Third Hokage let out a soft sigh, took a stack of files for this year's graduates from his drawer, and began to read.

Uchiha Clan Compound, Sasuke's home.

After finishing dinner, Sasuke did not start training immediately. After leaving a Shadow Clone in the house, he went down into a basement he had newly constructed in his home.

Walking into the basement, he found a spacious, clean room with a medium-sized laboratory bench placed in the center.

The surrounding area was filled with surgical scalpels, razor blades, small tweezers, small round needles, syringes, gauze, a microscope, and various other medical instruments.

Sasuke first went to a corner of the room, took out a small cage, placed it on the laboratory bench, and opened it.

Appearing before his eyes were two lively, energetic, and robust white mice.

However, the moment these two mice saw Sasuke, they were immediately struck with panic, squeaking incessantly.

Sasuke smiled slightly, revealing a kind expression. He took one of them out and began to carefully observe the physical changes in the mouse—or more accurately, to observe the mouse's eyes.

"Subject A, pupil size, shape normal, color normal."

"Conjunctiva color normal, smoothness and transparency normal, no obvious congestion, edema, follicles, or new growths."

"Cornea size, sensation normal, no obvious clouding, hemorrhage, pus, or foreign bodies."

Picking up the mouse and flipping back its eyelid, Sasuke scrutinized it for a while before writing in the laboratory log on the side.

Just after finishing writing, Sasuke picked up a small flashlight and shone it into the white mouse's eyes.

"The pupillary light reflex is slightly sluggish, likely because it hasn't fully adapted to the new eyes yet."

He gently pressed on the lacrimal fossa of the frontal bone above the mouse's eye socket, and seeing a small amount of regretful tears well up, Sasuke nodded.

"No redness, swelling, tenderness, or fistulas in the lacrimal sac area; the amount of secretion when pressing the lacrimal sac is normal, and there is no narrowing or obstruction of the lacrimal duct."

After checking carefully for a while longer and finding no obvious signs of discomfort in Subject A, Sasuke picked up the other mouse, Subject B, to begin the examination.

A long while later, Sasuke placed both mice back into their small cage and let out a long sigh of relief.

"Looking at it this way, my eye transplant surgery can be considered a success!"

These two mice were the test subjects he had specifically selected for the transplant; not only were their blood types identical, but even their iris diameters and pupil sizes were extremely close, meaning the margin of error was negligible.

"Medical Ninjutsu really is a bug-like existence; it's simply inconceivable."

One must know that Sasuke had only performed the eye-swapping surgery on the two mice yesterday, yet in just one short day, both mice had already begun to adapt to their new eyes.

However, there was a precedent for this; during the Third Shinobi World War, Nohara Rin had performed a hot-swappable, plug-and-play transplant surgery.