Tsunade's announcement of the live experiment's success undoubtedly meant another S-rank mission would be added to Uchiha Shinji's record.
Of course, that wasn't what Shinji cared about!
After a brief moment of celebration, the research group dove back into work.
Tsunade compiled the live experiment data into a report and headed straight to the Hokage Building. The remaining team members either cleaned up the site or examined the physical condition of Upper Moon Five.
Shinji didn't stick around. Taking advantage of everyone's distraction, he quietly slipped away.
By the time he returned to the Shinobi Academy, it was already afternoon dismissal time. He waited at the gate and soon spotted Shion coming out.
"Shinji!"
Waving from afar, Shion bounced over to Shinji with a spring in her step.
Ever since secretly joining Shinji's Akatsuki organization and training in "Water Breathing" under his guidance, Shion had regained her former liveliness.
The sense of duty to save the ninja world, coupled with her daily growing strength, had fully restored her confidence!
Shinji smiled. "Come on, my treat!"
Shion looked puzzled. "Did something good happen?"
Shinji merely nodded, saying nothing more at the crowded school gate.
After dinner, Shinji and Shion arrived at a secluded training ground. He shared the news of the Third-Generation Aging Agent's successful live experiment. "While we achieved success with Upper Moon Five, our real target is the far stronger Demon King. We need to test the Third-Generation Aging Agent's efficacy on even stronger demons!"
"Stronger demons!?" Shion was confused and pressed, "Isn't Upper Moon Five strong enough?"
"It depends on who you're comparing it to!" Pausing, Shinji explained, "Aside from the Demon King, only Upper Moon One and Upper Moon Two are truly exceptional. The demons after them feel somewhat like filler."
Shion grasped his meaning. "Shinji, you want to test the Third-Generation Aging Agent on Upper Moon One and Upper Moon Two?"
Shinji nodded slightly. "Not just to test the drug—I also want to see if your sealing techniques work on high-ranking demons!"
This time, Shinji wouldn't bring Sasuke.
After all, Sasuke's right eye's dojutsu power hadn't fully recovered, and he couldn't even use Susanoo. Bringing him now might result in him getting cut down with a single strike.
"Awesome!" Hearing it was time for real combat, Shion clenched her fist excitedly and asked, "So, who's our target? When do we leave?"
"Our target is Upper Moon Two! As for when we leave…" Shinji chuckled lightly, placing a hand on Shion's shoulder. "Right now!"
In an instant, a dim yellow light flashed, and Shinji and Shion vanished from the training ground.
When Shion opened her eyes again, she found herself in a world of ice and snow, surrounded by a blanket of white flakes.
Looking around, she asked, "Where are we?"
"Probably the Land of Iron," Shinji replied.
As he spoke, he pulled out two Akatsuki hooded red-cloud cloaks and two masks, tossing one set to Shion.
Sasuke's previous battle with Upper Moon Two had taken place at the border of the Land of Earth and the Land of Waterfalls. Afterward, Upper Moon Two likely fled northeast, escaping into the samurai-controlled Land of Iron. Thus, the Lampbearer had brought Shinji and Karin directly here.
"This is my uniform?"
Shion gleefully caught the hooded red-cloud cloak and swiftly put it on.
Then she picked up the mask, about to put it on, but upon seeing the monstrous pattern, she pouted. "Shinji, why is my mask like this?"
Shinji casually asked, "What's wrong?"
Shion said, "Shouldn't my mask have a miko pattern?"
Shinji explained, "It's precisely because you're a miko that your mask can't have a miko pattern! The point of the masks is to conceal our identities, so we need to mislead others as much as possible!"
"Makes sense!"
Convinced, Shion didn't dwell on it and put on the monster mask.
After changing, the two walked across the snowy plain.
According to the Lampbearer's senses, Upper Moon Two was hiding in a forest not far ahead.
Both possessed exceptional physiques, further enhanced by the stamina gained from practicing Breathing Techniques, so the blizzard posed little hindrance.
On the way, Shion asked, "Shinji, why choose Upper Moon Two?"
"Call me 'A' or Leader!"
Shinji instructed.
Shion nodded repeatedly. "Got it! You can't call me by name either—use my codename!"
Only then did Shinji explain, "Upper Moon One is a bit tricky, so testing the drug is easier with Upper Moon Two."
Shion frowned. "Tricky?"
Shinji nodded but didn't elaborate.
In truth, after the Grass Country battle, the mysterious figure's demon subordinates had scattered, but not all acted independently. Upper Moon One, for instance, had joined forces with Narume, who controlled the Infinity Castle, and another demon that Shinji's Lampbearer couldn't fully sense.
Based on intelligence gathered by the Hidden Grass Village, Shinji deduced that the mysterious demon with Upper Moon One and Narume was likely Muku, a Hidden Grass shinobi secretly turned into a demon by the "Grass Flower" faction, who had then activated the "Box of Paradise."
Since Muku was originally a shinobi from the ninja world, Shinji's Lampbearer couldn't sense him.
With Upper Moon One's demonized Tanjiro, Narume controlling the Infinity Castle, and Muku capable of activating the Box of Paradise, this trio was not something to be taken lightly.
Shinji's current priority was to counterattack into the Demon Slayer world, capture the mysterious figure, and find a way to save the ninja world. For now, he ignored these three demons, focusing his drug tests on the lone Upper Moon Two.
Before long, they reached the forest and, amidst the snowstorm, blocked Upper Moon Two's path.
"You again!"
Kokushibo's face darkened the moment he saw Shinji.
His gaze then shifted to Shion beside Shinji.
"Upper Moon Two… it really is Upper Moon Two!"
Shion was sizing up Kokushibo as well. When she clearly saw the "Upper Moon Two" markings in his eyes, she grew visibly excited.
"Be careful!" Shinji cautioned again before ordering, "Attack!"
Shion nodded eagerly, silently chanting a mantra. She raised her hand toward Upper Moon Two and shouted, "Sealing Coffin, Bind!"
With a whoosh, just as Kokushibo reached for his blade, he was trapped inside a small box that fell to the ground.