In the original work, Kuruyashiki Kenpachi is the seventh Kenpachi, and Sōya Azashiro is the eighth. So far, this timeline has not been problematic.
About five years passed like this, Sōya Azashiro continued quietly doing his Kenpachi work without engaging in any messy plans, which was quite good.
But for Jun, the 11th Division's style has changed drastically. Regardless of Sōya Azashiro's situation, his conversation with Jun back then might have actually had some effect.
Since he became Kenpachi, the 11th Division's 11th Division has drastically changed. Kenpachi has special killing authority, allowing him to execute members of the 11th Division at any time. In the most extreme cases, the 11th Division has fewer than eighty members remaining. Note that the 11th Division is a combat team of over three hundred people; he killed them all.
Therefore, Sōya Azashiro earned the nickname "Demon Kenpachi." From then on, the 11th Division's fighting spirit became comparable to the Second Division, arguably making them one of the top teams in terms of fighting spirit across all Gotei 13 —truly impressive.
However, observant people will notice that the group of veterans and trusted individuals left behind by Kuruyashiki Kenpachi all survived this catastrophe. This demonstrates that Kuruyashiki Kenpachi trusted reliable people, and the reputation of the 11th Division has nothing to do with certain individuals; that's a legacy of history.
If we go back to the original timeline, Kenpachi Sōya Azashiro would already be enjoying the scenery in the Muken. His successor would be the ninth Gosuke Kenpachi, who is now the 11th Division Vice-Captain Gosuke.
He rose to prominence because of Kuruyashiki Kenpachi. His parents had helped Kuruyashiki Kenpachi, and then, having a son late in life, they both passed away not long after. There was nothing they could do about it, since they were just residents of Rukongai.
Kuruyashiki Kenpachi once returned to his old home to visit the elderly couple who had helped him in the past. Being a sentimental person, he occasionally went back to see them. He learned that they had died and had a child. This led him to find Gosuke and bring him to the 11th Division. Since the Vice-Captain had just joined the First Division, he made Gosuke the Vice-Captain.
With the help of Kuruyashiki Kenpachi Gosuke his Reishi Sense and completed his Reishi Quality. However, he was essentially a peasant with little talent or ability; all his skills were mediocre. His ability to manage the 11th Division was entirely a legacy left by Kuruyashiki Kenpachi, with a group of old men helping him.
But as time went on, a group of old men who had joined the First Division went to the First Division, some died in battle, others died of old age. Kuruyashiki Kenpachi's generation lived hundreds of years ago; there was nothing they could do.
As a result, Gosuke Kenpachi gradually lost control of the 11th Division. After all, everyone knows what kind of people are admitted to the 11th Division. Then, the tenth Kenpachi, Kijōiwa Kenpachi, challenged Kenpachi and easily defeated Gosuke Kenpachi.
Then there's the 11th Division, which is arguably the worst 11th Division in history. Their discipline is unimaginably bad because Kijōiwa Kenpachi is a complete idiot, a total jerk. He knows nothing, can't do anything, and all he does is act tough. He relies entirely on his fists and his sword to get things done.
If someone like him were kept in check, he might be okay as a henchman, but making him a captain is giving him too much credit. He's the worst kind of person ever to be a leader. Fortunately, his tenure was short-lived; soon, the even Zaraki joined the 11th Division, and within days, he challenged Kenpachi, defeating him in two Kijōiwa Kenpachi.
In reality, Kijōiwa Kenpachi isn't that strong. How strong can someone be without brains? You can't become strong without understanding your true inner self. Besides, relying solely on talent without brains wouldn't get you anywhere. The fact that he became Kenpachi was truly a combination of perfect timing, location, and people.
Then there's the eleventh Kenpachi Zaraki, whom we're all familiar with. We'll talk about his story later, but in a sense, the current timeline has been altered by Jun.
Assuming Sōya Azashiro stops causing trouble, he won't be imprisoned. If he's not imprisoned, there won't be a ninth Gosuke Kenpachi, and the tenth Kijōiwa Kenpachi will have to challenge...
It's questionable whether someone like Kijōiwa Kenpachi could even get into the current 11th Division, but it shouldn't be difficult for Zaraki to join, because Zaraki isn't the scumbag type. He's a demon who likes to bully bad people, not ordinary people.
However, to put it simply, in my opinion, it was a pipe dream for Kenpachi Zaraki to defeat Sōya Azashiro in the early stages of the Kenpachi Challenge. As for whether they could achieve a 50/50 split after the initial power-up, it's uncertain, because Zaraki is purely brute force, while Sōya Azashiro completely counters brute force.
Also, Zaraki's Release was completely uncontrollable; he self-destructed before he could even land three strikes. But then again, the Captain-Commander himself thought Zaraki was dangerous and didn't train him, which was a good idea of his—a Zaraki idea indeed!
Incidentally, because of Sōya Azashiro's abilities, he could observe the entire Soul Society even from the Endless Hell, so he had met Zaraki and held him in low regard. As mentioned before, he completely countered Zaraki force; Zaraki couldn't do anything to him. How could Kenpachi possibly think highly of Zaraki?
Life returned to its original rhythm. With the Seven Swords acting as informants, Jun could receive a wealth of information from Hueco Mundo and the World of the Living. This information kept Jun from being idle, somewhat offsetting the melancholy of not being able to drink.
On the other hand, Jun still participates in the annual academy missions and occasionally World of the Living missions, running between the Undead and Hueco Mundo. He also begins new research in Soul Society, focusing on diseases, frequently visiting Rukongai and becoming acquainted with Tōsen.
At the academy, Jun discovered many acquaintances who would later become part of his life, such as the green-haired girl from the Visored, Mashiro Kuna, Isane Kotetsu; the two were in the same year.
A few years later, Mino Kuchiki became pregnant, and Sōjun was expecting a son. Jun was terrified that she might accidentally change the timeline Byakuya would be gone—that would be truly heartbreaking. However, a year later, a son was born, named Byakuya Kuchiki, and Jun's heart was finally at ease.
It might be hard to believe, but in the same year Byakuya was born, the current Third Seat of the Third Division Iba Chitetsu, had a son, the future Tetsuzaemon Iba, who is the same age as Byakuya! Who could tell!?
Aizen's father, Fumiyama Aizen, passed away, not in battle, but from old age. Jun attended the funeral to visit Aizen. It was then that Jun realized Aizen's heart had grown even colder; this was the Aizen who would later become, the Complete Form.
A man Tsubaki Jin'emon became the Vice-Captain of the Seventh Division. In the same year, Shimizu Isuzu became the Vice-Captain of the Thirteenth Division, while Jun remained the Fifth Seat.
Jun didn't care about the fight, and that bastard Takagi just wouldn't leave. The three or four seats sandwiched between them were incredibly uncomfortable, but it didn't matter. Jun didn't care, and neither did Takagi.
The Second Division's Vice-Captain, Marechiyo Ōmaeda down, and then Jun realized that Yoruichi Shihōin simply couldn't stay in the Second Division any longer. It seems that Marechiyo Ōmaeda's father is actually a loyal retainer—quite a rare find!
However, this makes Yoruichi Shihōin a true stepmother to Byakuya, though by seniority she's his grandmother. But since the Sōjun couple are still alive, Yoruichi doesn't visit them as often. However, Yoruichi has other places to go: the Shiba Clan, where the three siblings, Kaien Shiba, Kūkaku, and Ganju, were already born.
Yoruichi's distress only exacerbated the suffering of the Twelfth Division. Kisuke Urahara's mood plummeted, leading the Twelfth Division to frantically submit transfer requests, even to the Combat Division, rather than endure further torment under Urahara's monstrous rule.
Jun has basically met everyone who appeared in the original work, not to mention Rukia Kuchiki, but Byakuya was just born at that time, so where would he meet her?
Jun went to Hueco Mundo again. Upon arriving at the base, he saw Kuruyashiki Kenpachi and Oka drinking together. Kuruyashiki Kenpachi is now called Zennosuke Kuruyashiki and gets along well anywhere.
"It seems you've adapted well to this lifestyle."
"Haha, there's nothing we can do about it. But after being here for so long, I've realized you're absolutely right. How they face Soul Reaper is entirely influenced by us."
"That's exactly right. Before you have enough experience, what you need is knowledge, and then you can use experience to verify your knowledge. I teach them to distinguish right from wrong, and that's the most important thing."
Zennosuke Kuruyashiki smiled. "You're really something. So, what brings you here this time?"
"There is indeed something going on, but I've already figured out the solution."
Zennosuke Kuruyashiki was surprised, then congratulated him, saying, "Congratulations, but I thought you might have solved it a long time ago."
"No~", Chun shook his head, "The solution to the rule-based system is very difficult, which is also related to my lack of effort in comprehending it. I prefer the Kidō."
"Haha~", Zennosuke Kuruyashiki shook his head helplessly, "Geniuses like you are indeed capricious and willful. You can do anything like this. Everyone else is pursuing solutions, but you don't care at all."
"Ha~ After all, in my mind, 'Kai' is just a unique kind of Kidō," Jun snapped his fingers. "So the question is, what's above 'Kai'?"
"Hey~ hey~, Chun, what kind of dangerous things do you usually think about!?"
"Danger? No, not at all," Jun stated his thoughts. "Don't you think that right now, Soul Reaper are too weak compared to Arrancar? Even you only have the attack power to kill Arrancar, and the Arrancar have to give you face and let your Resurrection hit you. So it's strange, why? Why should Soul Reaper be weaker than Arrancar?"
Zennosuke Kuruyashiki's eyes lit up. "Yeah! Why?!"
"So, regarding the development paths of Soul Reaper and Hollows, I've discovered this to be true."
"Soul Reaper initially possess humanity, but lack Spiritual Power. Therefore, they must awaken and absorb Spiritual Power to grow. Reaching the peak of growth is the solution. For now, that's how it is."
"The contrast is with Hollows. Hollows possess Spiritual Power from the beginning, but they lack humanity and only have instincts. Hollows never had humanity until they reached the limit of Arrancar, at which point they began to gain humanity."
Zennosuke Kuruyashiki scratched his old face, somewhat puzzled, "You mean the Soul Reaper is going to abandon humanity?"
"It might be one path, but what I mean is, what the Soul Reaper wants is what the Hollows possessed from the very beginning: instinct!"
"Instinct!?"
"Yes!" Chun nodded heavily, "Instinct!!"
"I don't know. Maybe it requires accepting the power of the Hollow. Soul Reaper have lost their instincts for too long. Hollows gradually relinquish their instincts, while Soul Reaper pursue their instincts all at once. In this sense, we can see it as a kind of Heart Demon, which is extremely dangerous! Extremely dangerous!!"
After thinking for a long time, Zennosuke Kuruyashiki nodded. "That's interesting, very possible. Now that you mention it, I really think you're right. But how do we do it?"
"The power of the Hollow!" The two then turned to look at the Arrancar.
The Arrancar were intrigued, having heard everything. Starrk chuckled, "What? Do you need our power?"
Who wants to go first?
"I'll go first," Zennosuke Kuruyashiki, swinging his arms as he prepared to go.
"Okay, you continue, I'm leaving."
"Ha!?"
"I'm no use here. You have to overcome your Heart Demons yourself. Bye~"