Ever since his first visit to Kensei, Aizen had shut himself in his laboratory in the Rukongai. If not for the complete hypnosis ability of his Kyōka Suigetsu, he would have likely been declared a missing person by the Shin'ō Spiritual Arts Academy long ago.
In the dimly lit laboratory, Aizen's eyes were fixed on the test tube of spiritual particle solution in his hand, its faint blue light reflecting off his glasses. With a sigh, he removed his glasses and dripped a few drops of medicinal solution into his bloodshot eyes. Closing his eyes, he sat back in his chair for a brief rest.
He had been eating and sleeping in the lab for the past few days. As for the dormitory, anywhere without Kensei felt the same—cold and silent, giving Aizen, who had grown accustomed to Kensei's noise, a suffocating feeling.
Aside from the corpses of rebel soldiers preserved in nutrient tanks to prevent them from dispersing into spiritual particles, there were also quite a few living rebel members here. After all, Aizen was researching methods of physical regeneration; he couldn't very well experiment solely on the dead.
"Another failure..."
Watching as an experimental subject's body swelled after being injected with the fluid intended to regenerate a severed arm, then exploded from the inside, Aizen observed the viscous crimson mist inside the tank. Fragments of flesh were spattered and solidified against the transparent walls. He coldly recorded the new data on paper with his pen.
A Shinigami's body is composed of spiritual particles. He had thought this foundational theory would allow for rapid progress, but the consecutive experimental failures led Aizen to consider whether he should change his approach.
Rubbing his temples, Aizen decided to return to the dormitory for a night's rest. He had appeared too frequently lately on the battlefields where rebels clashed with Special Forces. Although no one could see his true face, continuing like this would inevitably lead to slip-ups. If caught, he would either be thrown into the Maggot's Nest or forced to defect from the Soul Society.
Moreover, the treasures Aizen had previously taken from the Tsunayashiro family warehouse were nearly depleted. He would need to be even more cautious with their use going forward.
Leaving the temporary laboratory, Aizen began walking towards the dormitory. Glancing at the gloomy sky, he wondered whether he should visit Kensei again. He had no idea how the boy was doing now.
On the other side, Kensei, having enjoyed a full day of attentive service from Yoruichi and Soi Fon, now felt utterly relaxed and comfortable. If he could have a few more people like that, he wouldn't mind getting injured every day.
The Hell Spring's therapeutic effect was truly excellent. If not for those two enchantresses, Yoruichi and Soi Fon, blocking his way, Kensei would have long since gone to report to Old Man Yama.
Damnable enchantresses, only good for disturbing my Daoist mind.
Kensei worried that visiting Yamamoto so late might disturb his rest. As the old man's most filial student, how could he possibly do something so harmful to his teacher's health! Resolutely, Kensei prepared to return to the dormitory, deciding to get a good night's sleep first.
"Yo, Sōsuke! Long time no see!"
Pushing the door open and seeing Aizen sitting on his bed, Kensei greeted him warmly, casually slinging an arm around his neck. Aizen felt as if a husky had just pounced on him, staring somewhat dumbfounded at Kensei's arm now resting across his chest.
"Your hands...?"
Aizen reached out in disbelief, touching Kensei's arm. He feared this might be a hallucination born of exhaustion, but feeling the familiar spiritual pressure beside him and the strong arm hooked around his neck, he finally confirmed Kensei was truly healed.
"Of course! Who do you think I am? The Chosen One, got it? A minor injury like this couldn't possibly trouble this great one!"
Kensei boastfully flexed and extended his fingers, even standing up to demonstrate a few martial arts forms to prove he was completely recovered.
"Sōsuke, why do you look so tired? Did you take advantage of me not being in the dorm and... indulge yourself quite a few times without me?" Kensei grinned wickedly, making a gesture universally understood by men. "Don't worry, we're all guys here. I get it!"
Understanding Kensei's implication, Aizen felt all the blood in his body rush to his head, making his temples throb. He realized that the version of himself who thought he'd gotten used to Kensei's noise was a complete fool. This guy was better off confined to a hospital bed.
Calming the high blood pressure Kensei had induced, Aizen considered whether he should research a divine medicine that could render someone mute, with Kensei as the prime experimental subject.
Pushing his slipping glasses back up, Aizen concluded that Kensei's rapid recovery was likely due to the hot spring effect he'd overheard Retsu Unohana mention earlier. Otherwise, she wouldn't have requested so many medicinal herbs from Kirio Hikifune.
"Tell me what you've been up to these past few days."
Aizen didn't believe for a second that Kensei would obediently stay in bed. His legs were fine, after all, posing no obstacle for the brainless oaf to go out and find some trouble.
"Oh, so much! First, Soi Fon came to my room saying she'd take care of my daily needs until I recovered. Then I took her outside to learn Shunkō..."
"Stop!" Cutting off Kensei's gushing, Aizen asked slowly, enunciating each word, "And who is this 'Soi Fon'?"
Listening to Kensei explain Soi Fon's background, Aizen couldn't help but laugh wryly.
What kind of luck was this? Getting injured and having a girl he coincidentally saved earlier come to serve him. And considering the state of Kensei's hands before, that healing hot spring surely couldn't have been a solo venture—otherwise, how would he have taken his clothes off?
The more Aizen thought about it, the heavier his head felt. Could it be that Kensei's earlier talk about having "three wives and four concubines" might actually come true?
But at least his injuries were healed. That meant Aizen could refocus his experimental efforts on the Hōgyoku.
Aizen's vision began to blur. The still-gesturing Kensei beside him split into several overlapping figures in his sight. Though noisy, the familiar, somehow reassuring clamor surrounded him. The fatigue from days in the lab washed over him like a tide, and Aizen slowly closed his eyes.
Feeling the weight on his shoulder, Kensei looked at the now-sleeping Aizen. He gently laid him down on the bed so he could rest properly.
Kensei looked down at Aizen, his expression complicated. The fact that Aizen had let his guard down and fallen asleep in his presence... Judging from the dust in the room, this guy hadn't been resting in the dorm during his absence either. It seemed Aizen had already begun conducting experiments in secret. He just didn't know how far along they were.
Sigh. Who knew if anyone had noticed? But given Aizen's cautious nature, it probably wasn't Kensei's place to worry.
Who knows where he got his research materials from? Corrupting a good kid!
But considering Aizen saw him as a friend and had never used Kyōka Suigetsu on him, Kensei felt he should help him if necessary—as long as Aizen didn't plan on outright rebellion.
As for the Hōgyoku? No big deal. The Tsunayashiro family had plenty of powerful Shinigami souls to spare, enough for Aizen to squander. He could always fish Mayuri Kurotsuchi out later. Let the Tsunayashiro family suffer a bit, and let Kurotsuchi shoulder the infamy—it wasn't like he cared anyway.
Kensei felt that even though he hadn't yet taken Yamamoto's position, he was already worrying himself sick over the stability of the Soul Society. Old Man Yama getting a disciple as good as him was worth losing an arm over.