"He couldn't even activate Bankai…"
"No wonder the Head Captain holds him in such high regard, always lamenting how he missed the chance to take him as a disciple because of a brief misjudgment."
"To stop a former captain from even using Bankai… What kind of strength is that?"
Chōjirō Sasakibe looked at Hirako Shinji—battered, bloodied, collapsed in a pool of his own blood. Then he turned his gaze to Aiyan, who stood there calm and composed, as if defeating a captain-level Shinigami was no different than taking a stroll.
He understood.
This wasn't just a clash between two Shinigami.
It was a complete overpowering—both as warriors, and as wielders of Zanpakutō.
As a Shinigami, Hirako was beneath Aiyan.
As Zanpakutō, Sakanade was inferior to Kōfuin.
And that's what created the overwhelming one-sided defeat.
"He is strong—really strong."
Unohana Yachiru, the First Kenpachi, spoke with a deep look in her eyes. Her gaze rested on the sheathed Zanpakutō at Aiyan's waist.
With her experience, wisdom, and power—being one of the oldest and most fearsome captains—Unohana could see what others could not.
Just like Genryūsai Shigekuni Yamamoto.
The moment she had seen Aiyan's Shikai, witnessed the strange and powerful nature of Kōfuin, she knew that this Zanpakutō was no ordinary blade.
[Your Zanpakutō is very pleased that you used her to completely dominate a Gotei captain, rendering Hirako Shinji unable to even activate Bankai. To reward you, she has revealed a new ability developed during her Bankai training—a perfected Shikai ability: "Throne of Heaven, Rule of One."]
Defeating Hirako Shinji wasn't just a battle won—it came with a gift.
Aiyan didn't just earn the awe of those watching; his Zanpakutō, Kōfuin, gave him her strongest Shikai technique.
"The ultimate form of the Kōfuin…"
"It's only Shikai, but its power already rivals—no, surpasses—most Bankai."
As Kōfuin's new ability, Throne of Heaven, Rule of One. unfolded in his mind, Aiyan couldn't help but smile in surprise.
This wasn't an ability that required complex technique, Zanjutsu, Hakuda, Kidō, or even speed. This alone—just this—was enough to dominate Soul Society.
Just then, a voice interrupted his thoughts.
"Ai…Yan!"
Hirako Shinji's voice, though hoarse and weak, reached him from behind.
"Hm? Need something, Captain Hirako?"
"Oh wait, I forgot."
"You're no longer the Fifth Division's captain. Just another member now."
"So please—don't call me by my first name."
Aiyan turned his head just slightly, casting a sideways glance toward Shinji, who was still struggling to lift his head from the blood-soaked ground.
"Cut the act."
"I hate you."
"If you don't kill me today, I swear—I'll kill you one day."
Shinji forced a grin, blood trailing down his lips.
"That so?"
Aiyan laughed.
It wasn't mocking nor dismissive, Just… amused.
"What… are you laughing at?"
Shinji expected anything—an attack, silence, even a retreat—but not that laugh.
It was too casual.
Too indifferent.
And he realized…
Aiyan truly didn't care.
"You don't understand, Hirako Shinji."
"I never once saw you as an opponent."
"You're not a captain anymore. You're a relic. A failed man lying in his own blood."
"From now on, whether you bark or whimper like a beaten dog, it doesn't matter. You no longer have the qualifications."
Aiyan turned and began walking toward the exit of the barrier—erected by Shiba Isshin himself.
It was a strong barrier, built to contain captain-level battles.
But Aiyan walked through it as if it didn't exist at all.
"Honestly, I thought you'd go back and kill Hirako Shinji," Isshin said, standing outside.
"Good thing you didn't. That would've been reckless."
"It means you're still listening to me... still see me as your teacher, at least a little."
Aiyan looked calm.
"No."
"He's not worth killing."
Aiyan's voice was dismissive.
Kill Hirako Shinji?
What a waste.
This man was once captain of the Fifth Division. That title alone made him a valuable resource.
In the whole Seireitei, how many other "advanced research specimens" like him could be found?
Killing Shinji with a single strike might look dramatic, but that would waste a potential treasure.
Why would he waste him?
Especially now, when he had so much to prepare.
Over the last month, not only had his own Reiatsu, Zanjutsu, and Shunpo grown rapidly—but so had his "brother".
His Zanpakutō was already at the edge of unlocking Bankai. It was just a matter of time.
His Reiatsu had reached the level 12 Rank.
As for Kidō—he could already cast all Hadō and Bakudō below #80 without incantation, and their power wasn't any weaker than full-chant versions.
His Kendo had evolved on its own—born from observing Unohana Yachiru's technique, and now a unique style of its own.
Even though he didn't use Hakuda much, he was already stronger than Yoruichi in that field.
And in terms of Shunpo?
Yoruichi might seem like the fastest, but Aizen was already on her heels—and gaining fast.
Although Aiyan could still defeat him easily, he knew—Aizen was catching up.
And that meant trouble… and opportunity.
Because Aizen's actions were becoming more daring.
Three days ago, using Kyōka Suigetsu's power, Aizen had begun sneaking into all corners of Seireitei libraries, databases, and the12th Division Research center.
Everything except the Great Spirit Book Gallery was within his reach.
With the information he gathered, Aizen was already preparing for the Hollowfication Experiment.
Aiyan, seeing this unfold, obviously had no intention of killing someone as valuable as Hirako Shinji.
After all—
If his Zanpakutō and Reiatsu one day hit a wall…
If he needed to break past the limits of a Shinigami…
If he needed to master the Hollowfication Process…
Then the Hōgyoku would eventually come into play.
And for that?
He'd need high-quality "experimental material."
Just like Hirako Shinji.
...
Hey guys, I've written a one-shot story as an extra plot for this fanfiction.It's titled "Memories and System Awakening."
Let me know how you liked it—and if you'd want more bonus stories like this in the future,
Also, what kind of one-shots would you like to see next? More backstory moments like this? Or maybe some romance-building scenes between Aiyan and the heroines?
Tell me in the comments