Having secured the secrets of the Kaiten, Kei felt no immediate urge to master its physical movements. Instead, he poured every ounce of his focus and chakra into Shinnō's Body Revitalization Jutsu.
The sprawling new Mental Sanatorium officially opened its doors after a few weeks of frantic construction. With the facility's massive expansion came a flood of new civilian patients and a small army of hired medical staff.
However, Kei completely isolated himself from the daily bureaucracy, delegating every single administrative headache to Haru.
Having a fiercely loyal, highly competent assistant brought him profound operational peace of mind. While Haru managed the logistics and the public-facing clinic, Kei was free to vanish into the shadows and focus entirely on resurrecting his dead eyes.
Three months passed in a relentless blur of therapy sessions and subterranean training.
One quiet afternoon, after discharging his final patient of the day, Kei reclined in his office chair, intending to take a brief nap.
He hadn't been asleep for more than twenty minutes when he was abruptly awakened by a strange, sharp sensation. A deep, persistent itch was crawling directly behind his sightless eyes.
Out in the lounge, Haru was quietly organizing a stack of patient files. Hearing Kei shift restlessly and seeing his hand hover over his bandaged face, she immediately sensed something was wrong. "Kei-sama? Are you unwell?"
"My eyes," Kei murmured, forcing his hand down to suppress the overwhelming urge to rub them. "They are itching fiercely. I have not felt physical sensation in my optic nerves since the day I went blind. I believe the jutsu is finally taking root."
Haru dropped the files onto the desk, her eyes widening. "We need to get you to the subterranean ward immediately. The new scanners will be able to map the changes."
The two of them moved swiftly, bypassing the bright, public rehabilitation rooms on the ground floor and descending directly into the heavy steel depths of the true laboratory.
The new underground facility was a world apart from the cramped basement of his old clinic. Thanks to the staggering wealth they had extorted from the Hokage and the Main House, the room was lined with pristine, cutting-edge medical technology. Gleaming surgical tables, towering glass preservation tanks, and rows of complex monitors hummed quietly in the cold air.
Hearing the heavy vault door open, Shisui paused his shadow-boxing routine in the center of the room. Learning of the sudden development in Kei's condition, the Uchiha stepped closer, utilizing his own sensory perception to monitor the situation since he still adamantly refused to accept a transplant.
Kei calmly approached the surgical station. He snapped a pair of sterile gloves over his hands and, with practiced, chilling efficiency, extracted his own eyes. Having performed the gruesome self-surgery several times over the past few months, the procedure was now effortless.
He placed the dull, gray orbs into the sleek scanning machine and initiated the sequence.
As the machine hummed and clicked, reading the cellular structure, a rare, genuine thrill of anticipation fluttered in Kei's chest.
In truth, the past three months of relentless, unrewarded effort had tested even his monstrous discipline. He had channeled the Body Revitalization Jutsu through his skull countless times, day after night, without a single microscopic sign of healing.
Initially, his mind had remained a fortress of calm. But as the weeks dragged on, a tiny, poisonous seed of frustration had inevitably taken root.
As a master psychiatrist, Kei intimately understood the insidious pathology of anxiety. He knew how a lingering, formless dread could slowly escalate into a suffocating panic, triggering insomnia, erratic heartbeats, and eventual psychological collapse. He had treated countless elite shinobi whose minds had utterly shattered under the weight of such prolonged, hopeless tension.
But Kei was the absolute master of his own psyche. He had recognized the creeping frustration for exactly what it was, isolated it, and ruthlessly snuffed it out through cold, calculated self-suggestion. He had simply reminded himself of the blacksmith's creed: the iron only becomes steel after a thousand agonizing strikes of the hammer.
He had forced himself to be patient. And now, the hammer had finally struck a spark.
The machine chimed softly, spitting out a long scroll of medical data.
Haru grabbed the parchment, her eyes darting across the ink. "The primary and secondary ocular blood vessels are still heavily occluded. There is no change in the blockages..."
She paused, her breath catching in her throat. Her voice suddenly spiked with raw excitement. "Wait. The cellular activity is still registering far below a healthy baseline... but it is no longer zero! Kei, there is a cluster of entirely new, living cells regenerating along the optic nerve!"
Although the scan was far from a total cure, the shift was monumental. The dead tissue was finally waking up. It was absolute, undeniable proof that Shinnō's jutsu possessed the power to reverse the necrosis.
"If the regeneration continues at this pace, you might truly reclaim your sight," Shisui murmured from the shadows, a heavy sigh of relief escaping his lips. A stronger, fully weaponized Kei meant a significantly higher chance of survival for the Uchiha clan.
"This validates the theory," Kei said, taking a slow, steadying breath to temper his elation. "The jutsu forces the necrotic cells to divide and conquer death. However... it does not possess the mechanical capability to clear the physical blockages choking the blood vessels."
"To fully restore the Byakugan, I will have to invent a surgical methodology to physically flush the dead blood from the veins."
"Do we possess the technology to perform that kind of microscopic surgery?" Haru asked, looking at the rows of machines.
Kei pondered the obstacle. "I cannot be certain. I lack hands-on surgical experience with living ocular pathways. Therefore, I will need to conduct a rigorous series of live human trials to perfect the clearing technique before I risk slicing into my own eyes."
With that dark necessity established, Kei turned his bandaged face toward his assistant. "Haru. What is our current financial liquidity?"
Haru didn't even need to check the ledgers. "We are nearly broke," she admitted frankly. "Forging the heavy steel cells for the prison ward consumed a massive percentage of the budget, and purchasing these black-market scanners drained the rest."
"The funds we currently hold are only sufficient to keep the public clinic operating smoothly. At best, you could afford to acquire and sustain two, perhaps three disposable test subjects before we default."
Advanced medical research, particularly illegal vivisection, required an astronomical burn rate of cash. The machines were a one-time purchase, but the surgical materials, sedatives, life-support fluids, and the steep cost of bribing corpse smugglers added up rapidly. If Kei intended to run a full-scale testing ward, their current bank account wouldn't last a week.
Casually popping his eyes back into his skull and reconnecting the nerves with a brief flash of healing chakra, Kei sighed. "In that case... the Main House will simply have to endure another minor financial burden."
Haru immediately understood. She stepped over to a desk, retrieved a fine piece of parchment and an ink pen, and handed them to the doctor.
Kei flawlessly penned another heartbreaking, deeply manipulative letter detailing a sudden, tragic lack of resources preventing him from fully serving the Will of Fire. He handed the extortion note to Haru, instructing her to deliver it directly to Clan Head Hiashi in the morning.
Watching the casual robbery unfold, Shisui crossed his arms, his scarred face twisting into a deep scowl.
"You are treating the most powerful clan in the village like your personal vault, Kei," Shisui warned. "You can bleed them with guilt trips once or twice, but if you push it, the elders will snap. They are paranoid, not brain-dead. They won't let you siphon their wealth indefinitely."
"You are entirely correct, Shisui," Kei agreed smoothly, leaning against the surgical table. "In fact, my intuition strongly suggests that this upcoming request will be the absolute final time I can safely drain their coffers without triggering an aggressive audit."
Kei began to silently calculate his options. He desperately needed to secure an independent, massive, and entirely untraceable river of wealth.
Opening legitimate side businesses or investing in merchant caravans was far too slow. He didn't have years to build a financial empire; he needed millions of ryo now.
After running through dozens of illicit scenarios, a brilliant, highly violent idea blossomed in his mind.
Kei slowly turned his head, his sightless, smiling gaze locking directly onto the Uchiha.
Over the past three months, Shisui's physical conditioning had been exceptional. While he still lacked the apocalyptic power of his Mangekyo Sharingan, his muscle density, chakra reserves, and lethal instincts had recovered to nearly seventy percent of their original peak. He was more than capable of slaughtering standard Jonin.
He was the perfect, untraceable weapon for a heist.