Kazuma bid Neliel farewell and continued his journey through Hueco Mundo alone.
From the moment he arrived, his goal had been singular: learn Bankai and become stronger.
After spending so much time in the desolate realm, his Zanjutsu, Hakuda, Hohō, and Kidō had all improved significantly, but the secret of Bankai still eluded him.
"Raitei," Kazuma called out, entering his inner world.
"I'm here. I want to learn Bankai," Kazuma declared, skipping the pleasantries.
Raitei sighed from his throne. "You're here again. Every time you visit, you make the same demand. You are persistent sure, but Bankai is not something you learn just by asking. You do not understand its meaning. Go back. When you finally understand what I'm talking about, you may return. I do not wish to see you right now."
Raitei waved a hand, and Kazuma was forcibly ejected back to reality.
Kazuma stood in the quartz desert, bewildered.
He didn't know what he had done wrong or why Raitei refused him.
Was it really because he hadn't grasped the true meaning of Bankai?
What was the true meaning?
'It seems I won't be learning Bankai from Raitei anytime soon. I'll have to rely on my own comprehension. I should leave Hueco Mundo and return to the Soul Society.' Kazuma opened his eyes.
He had assumed Raitei would just hand over the power, but it seemed he had to earn it through understanding.
Kazuma stood up, preparing to leave.
'What is the essence of Bankai? It isn't just a simple multiplier of power, but an evolution of the soul. A breakthrough in one's state of mind. Perhaps only when I truly align with my blade can I master it.'
Kazuma drew his Zanpakutō, turned the key in the air, and opened a Sekaimon.
Stepping through the gate, he entered the Dangai—the precipice world connecting the realms.
The flow of time here was distorted, a ratio of 2000 to 1 compared to the outside world.
'This place is bizarre.' Kazuma looked around the dark, confined corridor.
He knew the Dangai was perilous.
If he encountered the Kototsu—the sweeping current cleaner—he would be obliterated.
To survive the Kototsu, one had to completely suppress their Reiatsu, or risk being devoured.
'Forget it, trying to train in here is too crazy. I'd better not risk it.' Kazuma pushed forward, traversed the Dangai, and finally stepped back into the Soul Society.
...
"You finally decided to come back? I thought you died in Hueco Mundo."
The moment Kazuma stepped out, Batsu'unsai materialized, having tracked his Reiatsu from the 8th Division.
Before she could vent her anger, Kazuma pulled her into a hug. "Yare yare! I'm back now, aren't I? Sorry to make you worry."
"You were gone for years, and you think you can brush me off with a hug?" Batsu'unsai grumbled, though she didn't pull away.
"Actually... I heard what you said that night when you were drunk. I was just pretending to be asleep."
Kazuma ruffled her hair. "So the Captain is a liar too. Alright! Go prepare the ingredients for nabe. I'll head to the First Division and report to the old man. I'm starving."
"Go on. Come back soon."
'I wonder exactly how much time passed in the Seireitei while I was in Hueco Mundo and the Dangai,' Kazuma thought as he hurried toward the First Division.
"Halt. This is the First Division headquarters."
Lost in thought, Kazuma stopped.
A man stood before him, wearing a white jinbaori over his Shihakushō. He had silver-white hair, golden eyes, and a sharp, aristocratic posture.
Kazuma froze.
'Wait a minute... isn't this the tragic character who gets one-shotted in the final arc?'
Chōjirō Sasakibe.
'It seems I was gone for quite a while. Even he has appeared.' Kazuma suppressed a laugh and bowed slightly.
"I am the 8th Division Lieutenant, Satou Kazuma. I have business with the Captain-Commander."
"8th Division Lieutenant?" Chōjirō frowned slightly. "I have not heard of Captain Batsu'unsai promoting a Lieutenant. Please wait here while I inform the Captain-Commander."
'Alas. Sasakibe's presence means he's already mastered Bankai and earned Yamamoto's respect. I've been training for two centuries and still can't use Bankai. So much for being a genius.'
"Thank you for waiting, Lieutenant Satou. The Captain-Commander is in the courtyard. Please follow me." Chōjirō led Kazuma inside, his mind full of questions.
When he had reported the arrival, Yamamoto had ordered the man brought straight to the courtyard, bypassing the reception room. Chōjirō couldn't fathom why.
"Captain-Commander, Lieutenant Satou has arrived. I will take my leave."
"Chōjirō, stay. I will introduce you," Yamamoto commanded.
"Yo! Captain-Commander, it's been a long time. What happened to the scar on your forehead?" Kazuma asked, feigning ignorance.
"You mean this? The kid standing beside you gave it to me. I have since changed my name to Yamamoto Genryūsai Shigekuni."
"I'm unworthy of such an honor. You think too highly of me, Captain-Commander," Chōjirō bowed low.
Yamamoto ignored the humility. "Let me formally introduce you. This is Chōjirō Sasakibe. He is my Lieutenant. His Zanpakutō, like yours, also governs lightning. However, his is recognized as the strongest lightning-type: Gonryomaru."
'The strongest lightning-type? I'd really like to test that,' Kazuma thought, a competitive spark igniting.
"Chōjirō, would you care to spar with Kazuma?" Yamamoto asked.
"Since the Captain-Commander commands it, I accept."
Hearing that the man before him also wielded lightning, Chōjirō was eager for a match.
...
First Division Training Grounds.
Kazuma and Chōjirō took their stances. "Lieutenant Sasakibe, after you."
Chōjirō didn't hesitate.
"Pierce, Gonryōmaru." He released his Zanpakutō, the blade transforming into a rapier, and lunged.
Kazuma dodged with Shunpo, drew his Asauchi, and struck back.
Sparks showered as the two exchanged rapid, heavy blows.
After several rounds, Chōjirō began to feel the pressure. 'Is he really just a Lieutenant? He is fighting me on even terms with a sealed blade. It seems I must use my Bankai to suppress him. Gonryōmaru is the supreme lightning Zanpakutō! even if he releases his sword, my Bankai will dominate.'
Chōjirō broke the clash and vaulted backward.
"Lieutenant Satou, I'm going to use my Bankai. I advise you to release yours, or you will be gravely injured."
"Bankai. Kōkō Gonryō Rikyū."
The Spiritual Pressure erupting from Chōjirō's blade pierced the sky.
The atmospheric electrons violently condensed, shrouding the Seireitei in heavy dark clouds.
A massive dome of electricity formed above them, splitting into eleven thick pillars of lightning that circled Chōjirō like a halo!
'Changing the weather itself... the strongest lightning-type huh. The oppressive weight is incredible, I won't survive this without a release.' Kazuma's demeanor turned deadly serious.
"Beneath the starry firmament, let thunder shatter the nine heavens. Slay gods and vanquish demons. Strike down, Raiteiken!"
Kazuma released his blade.
The surge of violent purple Reiatsu skyrocketed, clashing against the storm above.
'How is this possible?' Chōjirō's golden eyes widened. 'To reach this level of power with just a Shikai... His Reiatsu rivals a Captain's. It seems the title of 'strongest' is meaningless before raw power.'
Chōjirō gathered the eleven pillars of lightning onto his rapier and lunged, aiming to end it in one strike.
Kazuma raised Raiteiken high.
"Raishin no Sabaki (Judgment of the Thunder God)!" He pulled a bolt of pure, violet divine thunder down from the clouds, channeling it through his blade, and swung.
BOOM!
The collision of lightning was blinding.
The shockwave shattered the courtyard's stone tiles. Chōjirō was sent hurtling backward, his Shihakushō scorched and torn.
He crashed into the perimeter wall.
"Are you alright, Chōjirō?" Kazuma sheathed his sword, stepping forward to check the damage.
"Cough... I'm fine. Please, just call me Chōjirō." He was thoroughly humbled.
Kazuma had crushed his Bankai using only a Shikai.
His strength was terrifying!
"Thank you for holding back, Kazuma, and sparing me the sight of your Bankai. Though I must ask... might I have the honor of witnessing it?" Chōjirō asked.
Seeing Kazuma wince, he quickly added, "Forgive me. Forcing a shinigami to reveal their Bankai is presumptuous."
"Chōjirō, about that..." Kazuma rubbed the back of his neck, thoroughly embarrassed. "I actually don't know Bankai yet."
"Huh?" Two voices cried out in unison.
Even Yamamoto's stoic facade cracked.
'This kid hasn't even learned Bankai? What in the world?' Yamamoto frowned.
Chōjirō was equally stunned.
'He was this monstrous without Bankai? What would happen when he finally achieved it?'
The clash of lightning had attracted a large crowd of Shinigami.
"Let us move to my office. We are drawing an audience," Yamamoto ordered, cutting off Chōjirō's incoming barrage of questions.
Inside the office, Yamamoto turned to Kazuma.
"You said you haven't learned Bankai? That defies logic. Explain. I will help you diagnose the issue."
Kazuma relayed Raitei's cryptic rejection.
"Strange. Since you have mastered Shikai, Bankai is a natural progression of your bond with Raiteiken. You should not be locked out," Yamamoto muttered, stroking his beard.
Even the Captain-Commander was stumped.
"Chōjirō, you're confused," Yamamoto noted his Lieutenant's bewildered expression. "Kazuma joined the Gotei 13 two hundred years ago and mastered Shikai in less than a year. He then departed for Hueco Mundo to train. That's why you have never seen him."
'Joined two hundred years ago.'
'Mastered Shikai in a year.'
'Survived Hueco Mundo.'
'Doesn't have Bankai.'
'Crushed my Bankai with his Shikai...'
Chōjirō's mind went entirely numb.
The man was an anomaly!
As Yamamoto prepared to interrogate him further about Hueco Mundo, Kazuma bowed.
"Captain-Commander, it's getting late. Batsu'unsai is waiting for me to return for dinner, so I must take my leave."
Yamamoto, who had been gearing up for a lengthy debrief, paused.
His stern expression melted into a rare, genuine smile. "You little rascal. Go on. We wouldn't want you to keep her waiting."
Kazuma bowed again and exited the office.
Chōjirō stood frozen, his jaw slack, pointing a trembling finger at the door.
"He... he just..."
"He addressed Captain Batsu'unsai by her first name and said she is waiting for him for dinner. Captain-Commander, did I hear that correctly?" To Chōjirō, this was far more outrageous than Kazuma's combat record.
"You did," Yamamoto chuckled. "Kazuma and Batsu'unsai are very much involved."
'The terrifying bloodthirsty Captain of the 8th Division was playing house with her Lieutenant?' Chōjirō felt his worldview shatter into a thousand pieces!
...
Kazuma returned to the 8th Division barracks.
The moment he slid the doors open, he found Batsu'unsai prepping ingredients for nabe.
He immediately stepped in to help.
"You're back. Didn't the Captain-Commander keep you for a debrief?"
"He tried, but I told him you were waiting for me, so I rushed back."
"You told him that? He didn't try to cut you down?"
"He was actually very understanding, he practically shooed me out."
...
"Cheers! It's been two hundred years since I've had something this good."
After dinner, Kazuma and Batsu'unsai sat on the sloping tile roof of the barracks, enjoying the cool night breeze.
He recounted his survival in Hueco Mundo, seamlessly weaving in a few cheesy lines that made Batsu'unsai's face flush.
He thought back to his conversation with Raitei.
He still didn't grasp the true essence of Bankai, but he knew he would unlock it eventually.
'Time... I'm running out of time,' Kazuma thought, his smile fading slightly. 'Chōjirō has joined the Gotei 13. That means the Blood War—the first massive conflict between the Shinigami and Yhwach's Quincies—is approaching. I can't warn Yamamoto. If I tell him I'm a transmigrator and that Yhwach is coming to exterminate us, he'll lock me in the Maggot's Nest.'
Although he knew the Soul Society would ultimately win this first war, he didn't know the exact cost.
He knew the casualties were catastrophic.
The original Gotei 13 was largely wiped out or disbanded. The Genji School was reformed into the Shin'o Academy to replenish their decimated ranks.
What terrified him most was the lore.
After this war, Yamamoto's first-generation disciple, Shunsui Kyoraku, would take over as the Captain of the 8th Division.
That meant in the coming slaughter, Batsu'unsai would either be killed in action or forced to retire.
Kazuma wasn't willing to gamble with her life.
Gazing at the crescent moon, he reached over and firmly gripped Batsu'unsai's hand.
"Batsu'unsai. I will protect you."
She blinked, caught off guard. "What's gotten into you? You're acting weird. I don't need your protection. You just worry about surviving yourself..."