Despite Shinji letting the 'Upper Moon One' and 'Upper Moon Two' roam as bait for so long, the mysterious figure never appeared. This suggested either the figure was cunning enough to see through Shinji's intentions or had truly lost the Lampbearer's authority, rendering them unable to freely invade the shinobi world.
If it was the latter, the initiative was in Shinji's hands.
However, the thought that the Demon Slayer world might have been targeted by a Hegemon, whose influence was the highest level of contamination, made him hesitant.
Under normal circumstances, he should have already counter-invaded the Demon Slayer world to scout the situation. This very concern was why he couldn't make up his mind.
"If I get contaminated by the Hegemon while counter-invading the Demon Slayer world, could I end up drawing its gaze to the shinobi world?"
He felt a pang of apprehension.
In the end, it came down to time—he hadn't had enough of it to grow.
The mysterious figure in the Demon Slayer world, also a Lampbearer, had centuries to explore and master the 'Lamp's' abilities to their fullest extent.
Shinji, on the other hand, had only been in this world for three or four years. Barely after becoming a Lampbearer, he faced the Demon Slayer world's invasion. Everything was rushed—he hadn't even fully mastered his shinobi abilities, let alone delved into the 'Lamp's' potential.
The Lampbearer tasked with guarding a world was typically that world's strongest, but Shinji was nowhere near being the shinobi world's strongest!
"If only I had ten years…"
Shinji sighed.
Ten years from now, at twenty-two, his body would be fully developed, his physical prowess at its peak.
By then, even facing the mysterious figure, he'd have the confidence to take them down one-on-one.
Unfortunately, he didn't have ten years!
Given the current rate of contamination spread, the Demon Slayer world and the shinobi world might collide and annihilate each other in just a few years.
"When faced with great matters, stay calm!"
Shinji reined in his scattered thoughts, steadying his resolve.
The situation was dire, but not without solutions. The shinobi world was a deep and complex place. If push came to shove, unsealing and releasing Kaguya Otsutsuki was a viable last resort.
As the progenitor of chakra in the shinobi world, Kaguya's strength was undeniable.
If Shinji couldn't find a solution through the mysterious figure, he'd send Kaguya to the Demon Slayer world. Before the two worlds collided, he'd have her unleash the 'Expansive Truth-Seeking Ball' to destroy the Demon Slayer world preemptively!
Of course, releasing Kaguya came with consequences Shinji couldn't bear, so he wouldn't resort to it unless absolutely necessary.
Moreover, whether he could peacefully communicate with Kaguya was uncertain, making her release a desperate last-ditch option.
"The 'Upper Moon Two' and 'Upper Moon Five,' who were more active in the shinobi world, have been eliminated. The 'Upper Moon One' and 'Upper Moon Three' have been keeping a low profile, actively avoiding contact with shinobi world inhabitants, so the contamination spread is slower than I expected!"
With this thought, Shinji touched the 'Lamp' at his waist.
After communing with it, the 'Lamp' estimated a safe period of one year and eight months.
This meant the Demon Slayer world wouldn't collide with the shinobi world for at least that long, giving Shinji over a year to prepare.
However, the 'Lamp's' assessment wasn't entirely reliable, as it could be interfered with by other 'Lamps.'
"I need to find a way to eliminate the 'Upper Moon Five' before its memories of the Demon Slayer world are extracted during interrogation."
Memories were also a form of contamination!
Due to the 'Upper Moon Five's' powerful biological magnetic field, ordinary genjutsu struggled to maintain control over it. With Uchiha Shisui and Uchiha Itachi gone, the Hidden Leaf lacked skilled genjutsu masters.
Yakumo, a genius of the Kurama clan, had been instructed by Shinji to hold back during the 'Upper Moon Five's' interrogation, so the village's efforts had stalled.
Shinji mused, "Once the remaining demons in the shinobi world are dealt with, the contamination spread should slow even further, possibly buying a bit more time!"
He desperately needed time.
Whether it was Karin, striving for the Rinnegan, or Neji, Kimimaro, and 'H,' brewing the Tenseigan, they all needed time.
The Rinnegan and Tenseigan weren't ordinary dojutsu Bloodline Limits.
They were thresholds to the 'Six Paths' level. Even with all conditions met, accumulating sufficient chakra to attempt the breakthrough required time!
"For now, this will do."
Shinji let out a quiet sigh and drifted into sleep.
In the following weeks, Shinji took time to exterminate the demons scattered across the shinobi world. Many were bred in the Hidden Grass Village, with limited strength and low contamination levels.
Finally, through his 'Lamp,' Shinji confirmed the total number of remaining demons.
Nine demons remained in the shinobi world.
The 'Upper Moon One,' 'Upper Moon Three,' and the demonized Muzan were a group hiding in the Land of Water.
The 'Upper Moon Five' was captured by the Hidden Leaf.
The Hidden Rock, Hidden Cloud, and Hidden Mist Villages each held one demon.
One demon was in the Land of Fields, likely in the newly established Hidden Sound Village under Orochimaru's control, based on the 'Lamp's' positioning.
The final demon was in the Hidden Rain Village in the Land of Rain, most likely in the Akatsuki's hands.
Aside from the 'Upper Moon One' group, the other demons were controlled by various factions, making them difficult to eliminate.
However, these demons were mostly confined in top-secret labs with limited contact, slowing the contamination spread and giving Shinji time to plan.
The priority now was dealing with the 'Upper Moon Five' held in the Hidden Leaf.
The information possessed by an 'Upper Moon' demon far surpassed that of ordinary demons in contamination potential. The others could wait, but the 'Upper Moon Five,' under ongoing interrogation, could no longer be delayed. If the Hidden Leaf broke through and extracted Demon Slayer world information—or worse, learned about the Lampbearer—the contamination level could skyrocket.
Then, Shinji's estimated one year and eight months might no longer hold.
Time was what Shinji lacked most, so even if it meant taking risks, he had to eliminate the 'Upper Moon Five' as soon as possible.