Using the Lampbearer's ability to teleport freely when eliminating invaders, Shinji and Shion instantly transitioned from the icy Land of Iron back to the Hidden Leaf Village.
Shion asked curiously, "What an amazing ability! Was that the 'space-time ninjutsu' everyone talks about?"
"Sort of!" Shinji replied vaguely, then added, "You experienced real combat today. When you get back, reflect on it and think about any shortcomings you might have."
"Got it!"
Shion nodded, carefully stowing away her red-cloud cloak and mask.
Though just a uniform, it held profound significance for her.
Today's battle had also left a strong impression on her, especially Shinji's tactic of feigning weakness to lure the enemy into a trap with the simplest method. Even now, recalling it filled her with fascination.
After sternly reminding Shion to keep everything that happened today a secret, not to be shared with anyone, Shinji returned to his apartment alone.
Pat pat pat.
Turning on the shower, Shinji washed while closing his eyes to ponder his next steps.
The Third-Generation Aging Agent's performance was merely satisfactory. If the mysterious figure's flesh power was comparable to Upper Moon Two's, it might suffice. However, as the Demon King, the mysterious figure's flesh power was undoubtedly far stronger, casting a big question mark over whether the Third-Generation Aging Agent would be effective.
Fortunately, after days of intensive pharmacology study, his expertise had improved dramatically. Even working alone, he was confident in further optimizing the aging agent. Plus, he had the cheat-like dojutsu, Izanami no Mikoto.
Recalling his encounter with Upper Moon Two, he mused, "It doesn't need a major breakthrough. Just enhancing the potency to affect the mysterious figure will do."
Ultimately, Shinji was wary of the mysterious figure's bizarre Blood Demon Arts and its outrageously powerful regeneration.
He didn't expect the aging agent to kill the mysterious figure outright. He only hoped it could weaken its flesh power enough to make capturing it alive easier.
"In the end, it'll come down to my own strength!"
Sighing, Shinji set aside thoughts of optimizing the agent.
After his shower, Shinji slipped into a bathrobe and emerged from the bathroom, sitting at his desk.
No matter how much he planned, the priority was to counterattack the Demon Slayer world, capture the mysterious figure, and interrogate its true intentions for invading the ninja world.
This was the only way he could think of to save the ninja world.
With his current strength, however, invading the Demon Slayer world was far from secure. Who knew what the mysterious figure, in its desperation, might have done after fleeing back? For all he knew, the Demon Slayer world had already become a demon-ruled realm. Stepping in could mean facing an endless swarm of demons.
Thus, either his Samsara Eye Plan or Tenseigan Plan had to succeed to give him the confidence to counter-invade and capture the mysterious figure.
The aging agent was merely an aid; a pair of Samsara Eyes or Tenseigan was the true key!
Opening his notebook, Shinji reviewed his Samsara Eye Plan and Tenseigan Plan.
"With Karin, there's little more I can do. It's just a matter of waiting for her Eternal Mangekyo Sharingan to accumulate enough All Creation Power for a qualitative leap."
Shinji flipped past the pages related to the Samsara Eye Plan.
At this stage, his ability to assist Karin was limited. At most, he could provide chakra through the Wazunagi conduit to aid her final push for the Samsara Eye.
As for Sasuke, the backup for the Samsara Eye Plan…
He considered it briefly, then shook his head.
Sasuke had only recently awakened his Mangekyo Sharingan and hadn't even fused an Eternal Mangekyo, let alone transplanted First Hokage cells. Banking on him achieving the Samsara Eye in time seemed unlikely.
Still, Shinji was accustomed to preparing contingencies, so while he flipped past the Samsara Eye Plan pages, he mentally committed to continuing Sasuke's development.
Page by page, Shinji reached the section on his Tenseigan Plan.
Unlike the wait-and-see Samsara Eye Plan, the Tenseigan Plan was riddled with uncertainties.
The biggest hurdle was the chakra storage speed of Kimimaro and Neji.
Despite his recent focus on optimizing the aging agent, Shinji hadn't neglected Kimimaro and Neji.
Of the two, Kimimaro's worsening Bloodline Limit disease paradoxically resulted in higher-quality chakra stored in his "biological exoskeleton," so despite his sickly appearance, his storage efficiency matched Neji's.
Neji, however, despite his diligent efforts to store chakra in the "biological exoskeleton," was hindered by factors like age and aptitude, resulting in lower efficiency.
"Looks like another trip to the Moon is in order."
Shinji closed the notebook.
Without the chakra from the giant Tenseigan on the Moon, Neji would struggle to keep up with Kimimaro's storage efficiency.
Over the next few days, Shinji gradually shifted his focus from the research group.
Regarding further optimization of the Third-Generation Aging Agent, Shinji privately discussed the matter with the pharmaceutical team's shinobi. Learning from past mistakes, the team was quite interested and didn't see Shinji's efforts as redundant, offering insights he hadn't considered.
Combining their ideas, Shinji, through Karin, ordered the Hidden Grass Village to scour the ninja world for rare poisons needed to optimize the aging agent while conducting simulation experiments in his secret lab. Once the poisons were collected, he could use Izanami no Mikoto to attempt formulating the Fourth-Generation Aging Agent.
With the aging agent matter mostly settled, Shinji turned to advancing the Tenseigan Plan. He made arrangements to ensure no major issues would arise in his absence, then used Jikibi to notify Neji to prepare for another trip to the Moon.
Hearing the message in his ear, Neji's heart tightened. Every trip to the Moon was a blend of danger and opportunity.