As Tessai Tsukabishi's figure disappeared into the cavern entrance, only Ren Hasumi and Urahara remained in the hollow cave.
Urahara leaned against the workbench, arms crossed, studying Ren. "How has your progress been lately? Gained anything of note by Aizen's side?"
Ren nodded. "A fair bit, actually. He has allowed me to participate in some of his experiments. Based on my understanding of Kaido, I noticed some flaws in the spiritual pressure guidance nodes of his Hollowfication experiments. I used Kaido's principles to help him optimize them. The results were quite good, and he's kept me involved ever since."
Urahara's eyes narrowed slightly. "You were actually able to optimize his experiments?"
"Yes," Ren held nothing back.
Urahara suddenly smiled, a flicker of intrigue flashing in his eyes. "Well, that is truly fascinating." He stood up, walked over to the workbench, picked up his notebook, and flipped to a fresh page. "Going by that logic, the deeper you get into the experiments, the more you will learn and master, and the more dependent Aizen will become on you. Your importance will steadily rise, and you'll gain access to more and more."
Ren nodded. "Right. I can already access data from the peripheral experiments. And during the trials, I saw the Hogyoku."
Urahara's pen froze. "The Hogyoku..." He softly muttered the word, his eyes gleaming with sharp intensity. "If we can locate where Aizen is hiding the Hogyoku and take it..." He didn't finish his sentence, but Ren knew exactly what he was thinking.
"I actually have an idea," Ren suddenly spoke up.
Urahara looked up. "What kind of idea?"
Ren walked to the workbench, picked up a vial of Hollowfication serum, and examined it. "There is a man by Aizen's side—Kaname Tosen, the 5th Seat of Division 9. Aizen trusts him completely."
Urahara's eyes narrowed slightly. "Tosen Kaname? The blind Soul Reaper?"
"Yes." Ren set down the vial. "From what I've observed, his strength is remarkable. It is highly possible he has already achieved Bankai. He holds a vital position next to Aizen and executes many critical missions, serving as his right-hand man."
Urahara looked thoughtful. "You mean you want to push him out and take his place?"
Ren glanced at Urahara and nodded. Talking to a smart man certainly saved a lot of effort. "If I can replace him and become the one Aizen trusts most, we will be one step closer to the Hogyoku."
Hearing this, Urahara leaned against the workbench, lowering his head in contemplation. "It's a solid plan, but execution will be incredibly difficult," he finally said. "Anyone standing right beside Aizen must be one of his closest confidants. How long has Tosen been with him, and how long have you been around? This isn't something that can be pulled off easily."
"I know," Ren's voice was calm. "It won't happen overnight. It requires time, opportunities, and ideally, some... external factors."
Urahara stared at him. "Meaning?"
The corner of Ren's mouth curled slightly into a smirk. "A man like Tosen has his own weakness. His hatred for the aristocracy and his obsession with justice—these are all things we can exploit. If we can find the right opportunity, we might be able to diminish his importance to Aizen." He didn't finish, but Urahara already understood.
"You want me to dig into Tosen's background?"
Ren nodded. "The Stealth Force's intelligence network is perfectly suited for this kind of work. If we can uncover some key information regarding Tosen, we might find our breakthrough."
Urahara pondered for a moment, then nodded. "Very well. I'll utilize my connections within the Stealth Force to look into him. His record, his past, his relationship with Aizen—we'll dig up whatever we can."
Hearing this, a faint smile played on Ren's lips. "Who knows, we might just get an unexpected surprise."
Kisuke Urahara looked at him. "An unexpected surprise?"
Ren shook his head. "Hard to say right now. We'll discuss it after you find something."
The animosity between Tosen and the Tsunayashiro clan was something he could potentially manipulate. If Tosen were given the chance to stand face-to-face with the enemy he loathed most, Ren doubted he could keep his composure. Anger would become his greatest weakness.
Urahara nodded, walking back to the workbench to pack up his instruments. "By the way, I can give you a few pointers regarding the Black Coffin."
Ren looked up. "What kind of pointers?"
Urahara's back was turned to him, his hands never pausing. "In the path of Kido, while brute force can certainly bulldoze through inefficiencies, if the power is lacking, it's not purely an issue of spiritual pressure. The precision of the spell's construction can also be adjusted. The formula for Black Coffin requires maintaining the flow of spiritual pressure even as it compresses. Your current Black Coffin still has room for improvement."
Ren looked thoughtful.
"The spiritual pressure forming the Black Coffin must flow within the sarcophagus, constantly compressing and swallowing everything. The greater the pressure exerted by the Reiatsu, the more destructive the power becomes."
As Kisuke Urahara continued his explanation, fragments of Kido insights floated down.
[SYSTEM: Gained Advanced Kido Insights x1, Kido EXP +100]
The fragments merged into his body as Ren repeatedly simulated Urahara's words in his mind. He opened his eyes and raised his hand. Black spiritual pressure condensed in his palm, turning into a miniature cube. It was slightly larger than before, slowly rotating above Ren's palm. The spiritual pressure flowed inside the cube like a current of water.
Urahara's eyes narrowed slightly. "You grasped it that quickly? Impressive, as always."
Ren dissipated the Black Coffin, a faint smile playing on his lips. "I'm still a long way off."
Urahara shook his head. "Not that far." He turned back around and continued packing his instruments.
Ren watched his busy back, falling silent for a moment. "Urahara."
"Hmm?"
"Thanks."
Urahara's hand paused slightly, then he smiled without turning back. "You getting stronger is good for me too. Don't forget, we're in the same boat. Alright, we're done for today."
Ren nodded. "Got it." He turned and walked out.
"By the way," Urahara's voice echoed from behind, "Next time you come, I'll help you measure your spiritual pressure levels in your Hollowfication state. We spent all of today talking and didn't get much actual work done."
Ren didn't turn back, merely raising a hand and waving. His figure vanished into the darkness.
Urahara stood in place, watching the disappearing back as he sighed softly. "He's already mastered the Black Coffin... Just how far can this guy go?" He turned back and resumed packing the equipment on the workbench. The open page of the notebook was densely covered in data. He looked at it for a long while before closing the notebook.
"Kaname Tosen..." he muttered. "Let see what secrets you hold that make you align so deeply with Aizen's ideals."
Ren walked along the stone-paved streets of the Seireitei, the moonlight casting a long, drawn-out shadow behind him. The earlier conversation kept replaying in his mind.
Replacing Kaname Tosen and becoming Aizen's most trusted confidant. This path might very well be the key to what lay ahead.
He looked up, gazing into the distant night sky. The moonlight was cool, and the stars were sparse. Ren stared into the night, the corner of his mouth curling upward. Quickening his pace, he walked briskly toward Division 4.