Reincarnated As Shiba Clan’s Heir! (Bleach-Gin)

His voice echoed through the infinite expanse of his inner world, finding approval in the humming of the entity above. The radiant figure moved with a celestial grace as it granted Kazuki its ultimate power. "I shall bestow you my ultimate ability for this once. Before Bankai, you cannot use it again."

Then, just as abruptly as he had been whisked away, Kazuki was back in the verdant depths of the Rokangai forest. The momentary silence was replaced by the ambient noise of chirping birds and rustling leaves, grounding him back into reality.

In his hands, Kamijō Tenseiga had undergone a transformation. The blade was longer, radiant with an ethereal glow, as though it was crafted from starlight. The guard expanded into a larger, circular shape, with eight starburst protrusions reflecting the expansion of his inner universe. The handle now bore a deeper black, contrasting starkly against the glowing blade, and the silver thread wrapping it shimmered with an otherworldly luminescence. The sphere at the hilt emitted a soft, cosmic glow, encapsulating the ethereal beauty of the cosmos.

Aizen, who had been waiting with an unsettling patience, finished his earlier sentence. "—ter Kyōka Suigetsu!"

In response, Kazuki brandished his transformed blade, the ethereal light of Kamijō Tenseiga casting long, wavering shadows. With a newfound determination burning in his eyes, he aimed the blade at Aizen's head. His voice carried an authoritative resonance as he called out, "Kill, Shinsō!"

Aizen's eyes opened wide as Kazuki's sword flashed by his head, missing only by a hair's breadth. The blade, like a streak of silver, extended far beyond what would normally be possible, reaching to a hidden spot behind Aizen where the hollow had been lurking. It pierced through the creature's mask as a horrifying screech echoed through the verdant woods. Aizen, initially thinking Kazuki had missed his mark, soon realized Kazuki's true target. The surprise on his face was quickly replaced by an unsettling smile. He did not vocalize his thoughts, yet in his mind, he acknowledged the turn of events. Kazuki had seen his Shikai, and from now on, there would be no escaping Aizen's illusions.

While Aizen had been absorbed in his thoughts, Kazuki felt a strange sensation. It was not just the hollow's reiatsu his Zanpakuto had pierced, but also Aizen's. A sensation of power surged within him, different yet somehow familiar. The deep voice of Kamijō Tenseiga resonated in his mind, imparting an understanding of this newfound ability. "Kazuki, you've devoured your opponent's Reiatsu. You've temporarily gained his power, and you're now immune to it. Remember, that is the power of your Bankai. Be vigilant, he's crafty."

"Devoured his reiatsu?" Kazuki mumbled, reflecting upon the words of his Zanpakuto spirit. The transformation he had undergone was something beyond his initial comprehension. He could feel Aizen's power coursing through his veins, imbuing him with abilities foreign yet oddly familiar. The understanding dawned on him. His Zanpakuto was more than just a weapon. It was an entity capable of draining and temporarily mimicking an opponent's powers. He looked at Aizen, his countenance firm, his eyes filled with a new light of understanding.

Aizen's eyes opened wide as Kazuki's sword flashed by his head, missing only by a hair's breadth. The blade, like a streak of silver, extended far beyond what would normally be possible, reaching to a hidden spot behind Aizen where the hollow had been lurking. It pierced through the creature's mask as a horrifying screech echoed through the verdant woods. Aizen, initially thinking Kazuki had missed his mark, soon realized Kazuki's true target. The surprise on his face was quickly replaced by an unsettling smile. He did not vocalize his thoughts, yet in his mind, he acknowledged the turn of events. Kazuki had seen his Shikai, and from now on, there would be no escaping Aizen's illusions.

While Aizen had been absorbed in his thoughts, Kazuki felt a strange sensation. It was not just the hollow's reiatsu his Zanpakuto had pierced, but also Aizen's. A sensation of power surged within him, different yet somehow familiar. The deep voice of Kamijō Tenseiga resonated in his mind, imparting an understanding of this newfound ability. "Kazuki, you've devoured your opponent's Reiatsu. You've temporarily gained his power, and you're now immune to it. Remember, that is the power of your Bankai. Be vigilant, he's crafty."

"Devoured his reiatsu?" Kazuki mumbled, reflecting upon the words of his Zanpakuto spirit. The transformation he had undergone was something beyond his initial comprehension. He could feel Aizen's power coursing through his veins, imbuing him with abilities foreign yet oddly familiar. The understanding dawned on him. His Zanpakuto was more than just a weapon. It was an entity capable of draining and temporarily mimicking an opponent's powers. He looked at Aizen, his countenance firm, his eyes filled with a new light of understanding.

Kensei and Urahara emerged from the depth of the forest, their appearances marking the end of their unforeseen separation from the group. As they approached, Kensei's observant gaze landed on Kazuki. Noting the subtle transformation in Kazuki, his eyes narrowed slightly, "Is everything alright?"

Kazuki merely offered a small nod in response, not allowing the underlying turbulence of his emotions to break the surface. They began their trek back to where the rest of their class was, the atmosphere oddly subdued.

The journey was marked by a silence that allowed each student to be lost in their thoughts. Despite the shared experience, their interpretations varied significantly, leading to a multitude of emotions - a mosaic of curiosity, wonder, fear, and ambition.

Upon their return, Yoruichi, Lisa, Isane, and Mashiro gravitated towards them. Aizen and Urahara had wandered off on their own, possibly for a discussion of their own.

Amid the gentle hustle and bustle of the reassembled group, Isane's sharp gaze fell upon the weapon in Kazuki's hand. The keen observation was expected from her, given her natural affinity for details. "You awakened your Zanpakuto?" She asked, her words cutting through the surrounding chatter, her eyes widening a fraction.

Kazuki, in response, smiled subtly and unsheathed his Zanpakuto. The blade glinted in the soft sunlight, its transformation apparent, "Yes," he affirmed, letting his action speak louder than words.

Even his closest friends, the people he considered as his extended family, didn't question him about his Zanpakuto's abilities. This reaffirmed Kazuki's belief that Aizen's actions earlier had been out of line, inappropriate in their setting. But the day was not done. Soon, Master Yashido, their stern but fair mentor, arrived to round up the dispersed group. His piercing gaze swept over each student, counting, assessing, ensuring that they had all returned safe from their respective hunts.