(T/N: Fourth Chapter!)
With the stimulation of Kaidō, the Saketsu and Hakusui—previously suppressed by medication—were reactivated.
Reiatsu surged continuously into the Spiritual Pressure Core.
Nanatsuki and Hoshino Rie observed quietly for ten minutes but noticed nothing unusual.
"Sensei, does this mean the Spiritual Pressure Core transplant was successful?" Hoshino Rie asked, puzzled. She glanced at the readouts but couldn't find any abnormalities either.
"There don't appear to be any problems for now, but we still need to monitor her a bit longer," Nanatsuki replied, reviewing the data on the instrument. "Suture the incision first. After that, we'll observe for two hours before waking her."
Nanatsuki personally stitched the incision and then used Kaidō to accelerate the healing process.
A short while later, Saitō Rei's skin had fully recovered.
They didn't wake her. Instead, they continued observing her stats through the monitoring instruments.
"Saketsu: no abnormalities."
"Hakusui: no abnormalities."
"Spiritual Pressure Core: stable."
"Reiatsu fluctuation deviation: within safe margin."
"Heart rate: low."
Every ten minutes, Hoshino Rie recorded the data. These stats would later serve as crucial reference for creating Katori Batsu'unsai's personalized treatment plan.
Saitō Rei's condition remained relatively stable—all stats were within a manageable range.
After two hours, Nanatsuki finally let out a breath of relief. There were no critical issues with her spiritual body.
"Sensei, the anesthetic neutralizer is ready."
"Administer it."
"Understood."
Hoshino Rie injected the neutralizer into Saitō Rei's body.
Immediately, the monitoring data began to shift.
Hoshino quickly recorded the changes:
"Saketsu and Hakusui Reiatsu production increasing rapidly..."
"Spiritual Pressure Core: still stable..."
"Reiatsu fluctuation deviation: abnormal..."
"Heart rate: abnormal..."
"Her Saketsu and Hakusui haven't fully adapted to the new Spiritual Pressure Core. It's being rejected, which in turn is overstimulating the Saketsu and Hakusui," Nanatsuki said, placing his hand over the two points. Using Reiatsu guidance techniques from Kaidō, he began channeling Saitō Rei's excess Reiatsu out of her body.
By now, the anesthetic had spread through her system, neutralizing the earlier drug's effects.
Saitō Rei gradually regained consciousness.
"Am I... still alive?" she mumbled in a daze.
"Don't worry. The transplant was successful. Please stay calm and keep your Reiatsu under control," Nanatsuki said gently.
"Miss Rei, please take this medicine. It will help clear your head," Hoshino Rie stepped forward and handed her a prepared dose.
After drinking it, Saitō Rei's mind became noticeably clearer.
"Why can't I control most of my Reiatsu?" she asked in surprise, sensing something wrong with her spiritual body.
"There's no major issue right now, but you need time to adapt to the new Spiritual Pressure Core," Nanatsuki explained, continuing the Reiatsu-guiding technique. "Follow my flow—try to regain control over your Reiatsu."
"Okay..." Saitō Rei could sense a foreign current of Reiatsu inside her. She followed its lead, slowly reaching out to sense and control the energy.
Gradually, she realized she could now manipulate the Reiatsu within the Spiritual Pressure Core.
"I can control my Reiatsu again!"
A smile of surprise lit up her face.
Nanatsuki nodded. "Good. Remember that feeling."
"I just used Kaidō's guidance technique to open up the core's flow."
"From now on, you'll need to keep doing this yourself until the rejection response is fully gone."
"Because we were pressed for time during the shell's cultivation, this Spiritual Pressure Core is still far inferior to your original one."
"It can probably only handle up to Level 10 Spirit Power."
"For the next few years, you'll need to be very careful. If you deplete your Reiatsu entirely, it may overstimulate your Saketsu and Hakusui."
"If those two spiral out of control, your core won't be able to bear the load. After all, your Saketsu and Hakusui were far more developed than this new core."
Saitō Rei had originally reached Level 6 Spirit Power—a high-ranking officer, nearly Vice-Captain level.
But the new Spiritual Pressure Core came from a Reishi Shell at Level 10. The gap was significant. If she fully activated her Saketsu and Hakusui, the resulting Reiatsu might exceed the core's capacity.
Saitō Rei nodded repeatedly. "I'm lucky to be alive at all. And having even Level 10 Spirit Power again is more than I could ask for!"
Her condition appeared stable, though monitoring was still necessary.
Nanatsuki called in Saitō Akane and informed her: "The transplant is complete. Miss Rei is doing well for now."
Saitō Akane bowed gratefully. "Thank you both so much! If Katori-sensei ever needs anything, the Saitō family will do everything we can to help!"
"Make sure she rests well during this period. I'll be checking on her daily. I'll also prepare Reiatsu-suppressing medication to help her adjust," Nanatsuki said, then turned to Hoshino Rie. "You're off duty for now, right? Stay with Miss Rei and record her condition every hour or two."
"Yes!" Hoshino replied at once.
That evening, Nanatsuki returned to the lab and instructed Aizen Sōsuke to dispose of the failed Reishi Shells.
"Sensei, what should we do with Saitō Rei's remaining No. 4 Shell?" Aizen asked.
They had used Reiatsu growth serums to rapidly cultivate Saitō Rei's shells. Two had successfully avoided Hollowification.
Nanatsuki had chosen the one with the stronger Spiritual Pressure Core for the transplant.
The other still sat in its life-support capsule.
"Shell No. 4 only reached Level 20 Spirit Power, right? Still, it was grown from a seated officer, so it's got more potential than a regular Shinigami shell," Nanatsuki mused. "Dial the serum back to normal dosage and keep cultivating it. We'll use it for future Hollowification experiments."
He had a hunch—even with the Soul King fragments, those experiments wouldn't go smoothly. They'd likely burn through many shells before making real progress.
The more usable shells, the better. This one, at least, had no distortions—best to keep it.
"Understood." Aizen nodded and adjusted the shell's growth settings on its data card.
The lab was used by three people. Every operation had to be logged clearly to prevent mistakes.
At that moment, Nanatsuki's Denreishinki beeped with an incoming message.
He checked and saw it was from Headmaster Kotetsu Isane.
A sense of foreboding struck him.
She rarely contacted him this late at night.
Nanatsuki quickly asked, "Headmaster Kotetsu? Is something urgent?"
Kotetsu Ayane's voice came through the device:
"Katori-sensei, there's been an issue with the graduation examination. Please represent the Academy and head to the Dangai to assess the situation!"
—
The day before, Kakyō had accompanied her instructor and members of the Kido Corps to the Dangai.
Her graduation exam task was to assist the Kido Corps in handling and repairing spiritual barrier anomalies inside the Dangai.
The Kido Corps examiners would assess her knowledge and application of Kidō during the process.
"Kakyō, let me first walk you through the spirit barrier structures in the Dangai," said Sakai-sensei seriously. "You'll need to focus. These aren't covered in the Academy curriculum, so it's a bit advanced. Study them fast so you don't embarrass yourself in front of the examiners."
Kidō wasn't about memorizing incantations—it required adaptability.
The examiners wanted to test how quickly she could understand the barrier's workings.
"I understand! I'll do my best!" Kakyō nodded confidently.
In the past few days, she had been studying with her teacher and Senior Sister Yoruichi. She'd even visited the Shihōin estate to read reference materials, gaining a basic grasp of how the Dangai's spirit barriers functioned.
She followed Sakai-sensei through the Dangai, observing and analyzing the barriers.
Nearby, members of the 3rd Division were stationed to monitor the anomaly zones.
Kakyō even ran into her fellow disciple, Azashiro Kana.
"Kakyō, you got this!" Kana waved from afar.
Nanatsuki had already informed Kana in advance to help look after Kakyō.
"Oh, it's Kana..." Sakai-sensei chuckled. "I used to teach her Kidō class back then."
Kakyō and Sakai-sensei walked over.
"Sensei! Long time no see!" Kana greeted with a bright smile.
"It's been years. And you're already a seated officer! You've surpassed your old teacher," Sakai said warmly. "Katori-sensei's students all turned out amazing. Almost all of you made it to seated rank."
Kana had even become a high-ranking officer—something most Shinigami never achieve in a lifetime.
"I was just lucky to have good teachers, hehe!" Kana scratched the back of her head bashfully.
"Kakyō is your junior, right?" Sakai said with a smile. "She's here for her graduation exam. Make sure no Hollows sneak into the Dangai and interrupt us!"
"Leave it to me!" Kana thumped her chest. "Not a single Hollow's getting past me!"
"With a seated officer on guard, I feel a lot better," Sakai joked. "Anyway, I'm taking Kakyō back to continue analyzing the barrier structures."
"Good luck!" Kana waved them off.
As they walked, Sakai began her lesson:
"Remember, these long-term sustained barriers rely heavily on structural stability. Do you remember the three main factors affecting that?"
"Extend your hand. Feel this formation up close—this area's key to structural balance."
"It operates similarly to sealing-type spirit techniques. The examiners are sure to ask you about this part."
Occasionally, they'd encounter Kido Corps members actively repairing the barriers. But they were too focused to engage in conversation.
By evening, the Kido Corps had finalized the repair and upgrade plans.
They'd even discovered previously unnoticed vulnerabilities. The task now was not just to repair but to optimize the barriers.
It would take more time.
Once the plans were in place, the examiners finally turned to Kakyō.
"Kakyō, please explain this formation."
"This is a commonly used structure in sealing and barrier-type techniques..."
The examiners asked several more questions, and Kakyō answered them all with ease.
"Excellent. Your theory is solid. Now let's see how you perform in practice."
They brought Kakyō in to assist with the actual repair work.
Though she lacked direct experience with the Dangai barriers, her Kidō foundation was strong. After some observation, she quickly adapted.
"Kakyō's practical ability is impressive too. You're ready for the Kido Corps. You passed on my end!" one examiner declared. "I heard you're one of Katori-sensei's students—his reputation is well deserved!"
"Yes, you clearly put in a lot of effort," another examiner nodded. "You get top marks from me too."
Other examiners all agreed—Kakyō's performance merited an excellent evaluation.
"Congratulations, Kakyō! You passed your graduation exam!" Sakai-sensei cheered. "When we get back, your teacher better treat us to something. It's been too long since I've had Katori-sensei's cooking!"
"Thank you all for your guidance!" Kakyō beamed.
"Haha, you're officially a colleague now," one of the examiners laughed. "No slacking during the barrier repairs—this is your warm-up for the real job!"
"I'll do my best!" Kakyō nodded firmly.
And so, Kakyō began assisting in the barrier repairs alongside the Kido Corps examiners.