When asked such a question, Sasuke Uchiha's expression first became stunned. Only then did he frown tightly and ask back, "Is there any need to discuss that here?"
"There is."
Rei Kaguya nodded lightly. In his eyes were curiosity, confusion, and… doubt.
"As the shinobi world's highest combat power, you should have deeply experienced the powerlessness and helplessness of ordinary ninja when facing the Otsutsuki clan's warriors during your clashes with several of them. You should also have felt the fact that, in terms of raw strength, they had already suppressed you two."
"But what is strange is that after relying on what could be called almost lucky methods to defeat Momoshiki Otsutsuki and Kinshiki Otsutsuki, the two of you seemingly did not develop any desire to improve your strength again in preparation for the possibility that other Otsutsuki warriors might descend upon the shinobi world…"
"I cannot understand the reason behind this. Could it be that the two of you both coincidentally believed that your era had already passed, and that the warriors of the Otsutsuki clan should be left to your next generation to confront?"
This question not only made Sasuke Uchiha's expression turn somewhat strange, even Naruto Uzumaki, sitting beside them, could not help revealing an expression of self-doubt.
"I… do not know."
After thinking for a while, Sasuke Uchiha frowned tightly and gave an answer that was difficult to justify no matter how one looked at it.
"Why do you not know, Sasuke Uchiha?" Rei Kaguya pursued the matter relentlessly.
"Because I also do not know the specific reason."
Sasuke Uchiha released his right hand from the Kusanagi Sword and looked toward his empty sleeve. His eyes carried a trace of confusion and absentmindedness.
"Was it because I had already grown used to having no left arm? Or… was I still concerned about things I believed I had already let go of?"
"Are those things more important than repelling invaders who cross the sea of stars from the universe, intending to turn the shinobi world into nourishment for a chakra fruit once again?"
Rei Kaguya looked at Naruto Uzumaki's intact arms, then at Sasuke Uchiha's empty sleeve, and sighed in great speechlessness.
"You two, who knows what you are struggling over… Even if you intend to make way for the younger generation, this is not how you are supposed to do it, right?"
"Moreover, even the two of you, back then, only truly began to understand the truth of things and walk the path of saviors at an age three or four years older than your current children, right? During that period before then, you were more or less following stronger ninja and working hard to train and improve yourselves, were you not?"
Sasuke Uchiha said nothing.
Naruto Uzumaki also showed the guilty expression of someone caught by Iruka Umino in class and not daring to say another word.
In the end, it was Sasuke Uchiha who spoke and gave an answer to this question that seemed more acceptable.
"Naruto and I are different from you… We cannot trust Orochimaru's technology as a matter of course like you do, nor can we allow him to conduct unscrupulous research on the Demonic Statue of the Outer Path and the Ten-Tails."
"And the reason you were able to advance another step beyond our level on your side must have involved borrowing no small amount of power from Orochimaru and the Ten-Tails, correct?"
"You have resources in hand, yet because of all sorts of strange reasons, you put them aside, even preferring to seal them away forever rather than try to develop and use their power… You are the strange ones."
Rei Kaguya shook his head noncommittally and asked calmly, "Or are you truly planning to keep the power capable of opposing the Otsutsuki clan entirely in your own hands and those of your descendants, thereby realizing unconditional rule over the whole shinobi world?"
"Do not confuse our responsibility with your ambition, Fourth Mizukage!"
Sasuke Uchiha's gaze sharpened, and he refuted Rei in an icy voice.
"We once faced Kaguya Otsutsuki, who had sunk into madness and corruption because she was intoxicated by power. We also saw the pale earth plunged completely into deathly silence after Infinite Tsukuyomi was activated… A power that dangerous should be sealed away forever. That is what responsibility toward the entire shinobi world means."
"But if you lose to the Otsutsuki clan's later arrivals, the Ten-Tails will still fall into their hands again and become their tool for harvesting the shinobi world once more."
Rei Kaguya shook his head with a calm expression.
"The premise for all good and evil, all merits and flaws, rests on the continued existence of ninja, of humanity, of this collective and this civilization. If they are destroyed in one stroke, then no matter how noble and precious your convictions are, the final result will still only be becoming an insignificant wave in the long river of history, a single grain of sand in its current, swallowed and forgotten without causing the slightest ripple."
"Do you not feel that your words contradict what you said earlier about needing to return to a future where there are things worth protecting, Sasuke Uchiha?"
Sasuke Uchiha bit his lip and offered no further rebuttal.
Because he knew this reason did not hold.
And his decision to never reattach his arm, as well as his failure to try mastering Sage Art, which could partially bypass the Otsutsuki clan's resistance to ninjutsu, was likewise indefensible in every sense.
Let Boruto and Sarada confront Isshiki Otsutsuki, as well as enemies who might be even more dangerous and powerful than him?
How could Naruto and he possibly do something like that?
Watching Sasuke Uchiha fall silent, Naruto Uzumaki, who had already been convinced by Rei Kaguya earlier, sighed helplessly and took the initiative to speak to Sasuke, who did not know how to respond for a moment.
"Admitting that there are things we really did not do well, or even that we failed to notice we had become somewhat stuck in place, is not something unacceptable, Sasuke…"
"Have you accepted it, Naruto?"
Sasuke Uchiha looked at Naruto Uzumaki, whose chakra cloak was gradually becoming closer to the Otsutsuki clan's white magatama-patterned robe, and asked with complicated feelings.
"…All I know is that if time could go back to before Momoshiki and the others descended, then I would do everything I could to become stronger. Ideally, strong enough to defeat Momoshiki and Kinshiki working together all by myself. If that had been the case, Boruto would not have become a vessel parasitized by Momoshiki's Karma. And in that battle against Isshiki, Kurama would not have needed to burn his life in my place."
A bitter expression slowly appeared on Naruto Uzumaki's face, filled with helplessness and endless self-reproach.
Listening to Naruto Uzumaki say words so full of regret, Sasuke Uchiha also closed his eyes.
Then he slowly reached his right hand toward the position of the scroll he had previously carried, the scroll sealing the Otsutsuki clan's treasure, the Plow.
If that treasure he had taken back from Urashiki Otsutsuki had not been by his side when Momoshiki Otsutsuki used Boruto Uzumaki's body to suddenly launch an attack, then Naruto and he probably would have died there.
If that had happened, there would have been no journey into the past.
He and Naruto would no longer have been able to provide protection for the children who had yet to fully grow up, or for the families who still cared about them.
"So this is the reason we came to this era? To… correct the mistakes that can still be salvaged?"
Hearing Sasuke Uchiha's murmur, Rei Kaguya raised his brow slightly and affirmed it in a proud tone.
"You may as well be a little bolder and see this journey against the flow of time as the starting point of the shinobi world's counterattack against the Otsutsuki clan high above."