Artificial light filtered down from the ceiling of the underground cavern beneath Sokyoku Hill, illuminating the vast, empty space. It was exceptionally quiet and adequately secluded; after all, no ordinary person would ever suspect someone of setting up operations directly beneath the execution grounds. That precise reason was exactly why Urahara Kisuke had chosen this location in the first place.
By the time Hasumi Ren arrived, Urahara was already tinkering with his equipment. Several vials rested on the workbench, glowing with a dim fluorescence while faint fragments of spiritual energy drifted through the air. To Ren's surprise, however, there was another person standing right behind Urahara.
Tsukabishi Tessai.
Ren paused mid-stride, his gaze darting between the two men.
"Don't be nervous," Urahara said without even looking up, his fingers adjusting a dial on one of his devices. "The Grand Kido Chief is one of us."
Tessai stood to the side, his hands tucked neatly into his sleeves, his expression perfectly composed.
"I didn't expect us to meet again so soon, Hasumi Ren." He offered a brief nod, keeping his words sparse.
Ren nodded back in acknowledgment and walked over, his eyes landing on the row of vials. The last time they spoke, he had asked Urahara for agents that could stimulate Hollow powers, and Urahara had promised to deliver. Looking at the setup now, it seemed the man had made some rather extensive preparations.
"What are these?" Ren asked.
"The items you requested last time. I tweaked the formula a bit, so the concentration is significantly higher." Urahara finally raised his head, a rare look of seriousness on his face. "Mind you, I've never tested this on a human before. But given your unique constitution, you can consider this a... special edition."
Ren picked up a vial and held it up against the light. A dark red liquid swirled slowly inside the test tube, emitting a faint, undulating spiritual pressure.
"How do I use it?"
"An injection." Urahara pulled a syringe out from beneath the workbench. "Direct introduction into the body yields the fastest results."
Ren's hand paused slightly.
Urahara smiled, his tone entirely casual. "Don't worry, there shouldn't be any issues."
"Shouldn't be?" Ren's lips twitched.
"It'll be fine. Even if something does go wrong, the Grand Kido Chief is right here. If you happen to go berserk, he can pin you down without causing you any harm."
"So that's why you brought him along?"
Urahara chuckled at Ren's remark. "Of course not just for that. He's an accomplice I recruited. You could say today is the day I lay all my cards on the table for him."
Tessai cleared his throat softly from the side. "Lord Urahara, you summoned me under the pretext of disclosing an urgent matter. Does it involve Hasumi Ren? And what exactly did you mean by going berserk?"
Urahara glanced back at him and shrugged, a mysterious glint in his eyes. "You'll find out in just a moment."
Urahara began calibrating the machinery in front of him. Once everything seemed ready, he picked up the syringe and drew the compound from the test tube. Then, he looked at Ren with keen anticipation.
Ren fell silent for a brief moment before rolling up his sleeve to expose his arm. "Let's do it."
While Tessai watched with a furrowed brow, Urahara wasted no time. He found the right spot and plunged the needle in.
Ren noticed stray particles of spirit energy drifting away from where the needle met his skin. In the next instant, the moment the fluid was depressed into his arm, a scorching power exploded inside him, surging through his spiritual pathways like molten lava.
[SYSTEM: High-concentration Hollowification energy injection detected. Hollowification EXP +2000][SYSTEM: Hollowification level increased: LV1 → LV2][SYSTEM: Hollowification: LV2 (EXP: 1200/2000)]
The medicine was still being pushed in, but as the system notifications settled, the burning sensation gradually receded, transforming into Hollow spiritual pressure that assimilated smoothly into his body. Once the entire dose was administered, Urahara stared intently at Ren, his eyebrows knitting together.
'Huh? That's strange. Why isn't there any change? Shouldn't a mask or something be forming on his face by now?' Urahara was utterly baffled.
"Ren, do you feel anything out of the ordinary?"
Hearing Urahara's query, Ren shook his head. "No, just that the Hollow spiritual pressure inside me feels slightly more abundant."
Urahara scratched his head, pursing his lips as he blinked. This was clearly a departure from his expectations. Then again, Ren was someone who defied all conventional logic.
"Hmm... perhaps it's a matter of dosage. Let's try one more vial." Without waiting for a response, Urahara silently swapped the vial and prepared the second injection.
The second Hollowification solution was injected into his body.
[SYSTEM: Hollowification EXP +2000][SYSTEM: Hollowification level increased: LV2 → LV3][SYSTEM: Hollowification: LV3 (EXP: 1200/3000)]
Ren merely swayed slightly, showing no further reaction.
Urahara's expression became intensely focused, his eyes gleaming with the manic obsession characteristic of a researcher.
The third vial went in.
[SYSTEM: Hollowification EXP +2000][SYSTEM: Hollowification level increased: LV3 → LV4][SYSTEM: Hollowification: LV4 (EXP: 200/5000)]
Ren closed his eyes, feeling the sheer volume of power churning within him. The Hollow spiritual pressure surged from the deepest recesses of his soul, as if thoroughly awakened by an external trigger.
"Sufficient," Tessai's voice suddenly rang out. "Lord Urahara, though I am unaware of the exact nature of the experiment you and Ren are conducting, if you continue any further, his physical vessel might not be able to withstand it."
Urahara stayed his hand, assessing Ren's current condition before glancing at the remaining vials. He nodded. "True enough. Let's call it a day for now."
Ren took a deep breath, stabilizing the turbulent spiritual pressure raging inside him. He looked down at his hands; black sparks of spiritual energy flickered faintly at his fingertips.
"After pumping in so many vials, it's impossible for there to be zero effect. Ren, how do you feel right now?" Urahara inquired excitedly, noticing the subtle shifts in Ren's demeanor.
Ren flexed his fingers, causing the black spiritual energy to slowly recede. "Not bad. My Hollow spiritual pressure has increased significantly."
Urahara's eyes lit up. "Then how about testing out the Hollowification? The Grand Kido Chief hasn't witnessed it yet."
"Hollow...ification?" Tessai murmured softly under his breath. Immediately after, his gaze toward Urahara shifted drastically. "Lord Urahara, while I still do not entirely comprehend what you and Ren are up to, knowing your character, I trust this isn't some highly perilous experiment?"
Urahara caught Tessai's look. The Grand Kido Chief still maintained a tranquil countenance with his hands tucked inside his sleeves, but Ren noticed that his eyes were far more piercing than usual.
"Rest assured. Why else do you think I asked you to come along?"
Tessai nodded and turned his attention back to Ren. Seeing Urahara give him a subtle nod of affirmation, Ren closed his eyes and triggered his Hollowification.
The Hollow spiritual pressure erupted from his body. This time, it was far more concentrated than ever before. It marked the first time he had ever unleashed his Hollowification at such a high magnitude.
A dark red spiritual pressure spiraled around his body, condensing rapidly before blanketing his face. Out of thin air, a bony white mask began to materialize.
Where it could previously only cover half of his face, now, his entire visage was enveloped by a pristine, chalk-white mask. Intricate, multicolored patterns rippled across its bone-like surface. This time, the contours of the mask were significantly sharper, with a crimson light gleaming ominously from the hollow eye sockets.
His spiritual pressure underwent an instantaneous mutation, completely saturated with the violent ferocity and raw intimidation characteristic of a Hollow—a stark contrast to his usual spiritual signature. Ren felt the immense, exponential multiplier to his overall power, astonished by the sheer enhancement granted by a higher tier of transformation. This was the true strength of Level 4 Hollowification.
Not far away, Tessai's pupils shrank to pinpricks. He stared at Ren's transformation in absolute disbelief.
"Th-this is..."