When Isshin and Ryuken crashed through the shop doors in a battered state, carrying the unconscious Masaki, Kisuke Urahara was crouching behind the counter repairing an old radio.
"Oh my, isn't this Captain Shiba?"
"Although I said you were welcome here anytime, this kind of 'gift' is a bit too heavy."
Urahara pushed up the brim of his hat. The moment his eyes, hidden in the shadows, fell upon Masaki, his previously frivolous expression vanished completely.
On her pale skin, a black hole throbbed hideously on her chest like a greedy vortex.
"Mr. Tessai, please open the barrier immediately."
"Understood."
The burly man was no ordinary handyman, but the former Grand Kido Chief, Tessai Tsukabishi, who had 'defected' from the Soul Society alongside him.
Under his guidance, the group protected Masaki, who was now sealed by the barrier, and quickly hurried to the underground training ground.
Ryuken Ishida stood beside the unconscious Masaki Kurosaki, his mind completely blank.
"Damn it... why did it turn out like this!" A suppressed, low growl escaped through Ryuken's clenched teeth.
"Well now, Mr. Quincy, please calm down first."
Kisuke Urahara walked over to Masaki, gently tapping his fan against his palm. "Before we proceed with the treatment, I must first explain exactly what has happened to Miss Masaki."
"Her condition is not an isolated case... I have been researching this for nearly a century..."
"A century?!" The two men opposite him exclaimed in shock.
"That's right. Miss Masaki's symptom is known as [Hollowfication]." He spoke coldly, as if recalling unpleasant memories.
"Hollowfication is the process of injecting a Hollow's soul into another soul, causing the boundary between the souls to collapse in order to ultimately achieve ascension..."
"Although it was originally intended to strengthen a Soul Reaper's soul, in reality, after Hollowfication, the soul will eventually become an irrational monster and undergo uncontrolled self-destruction..."
He extended a finger and pointed at the deathly pale Masaki. "Namely, [Soul Suicide]."
"What?! Then hurry up and restore Masaki to normal!" Ryuken Ishida shouted anxiously.
Kisuke Urahara shook his head. "Restoring her to normal is impossible. Hollowfication is a technique that cannot be controlled..."
Isshin Shiba also spoke up anxiously. "Then what do we do? Are we just going to sit here and watch Miss Masaki die?"
Urahara added, "While restoring her is impossible, we can at least save her life..."
"How?"
Facing Isshin Shiba's question, Kisuke Urahara pointed sequentially at Ryuken, Isshin, and Masaki.
"To prevent Soul Suicide, we need to inject something opposite to Hollowfication into the soul to maintain its balance."
"For example, injecting a vaccine that fuses Quincy power and a human soul into a Soul Reaper suffering from Hollowfication symptoms can stabilize that Soul Reaper's condition..."
"That's way too complicated, I didn't understand a word of it!" Isshin Shiba interrupted Kisuke Urahara's explanation in confusion, speaking bluntly. "Why don't you just tell me exactly what needs to be done right now!"
"Alright, alright, Captain Shiba. I'll give it to you straight."
"To save Miss Masaki, a Quincy, we must... use your powerful Soul Reaper powers as the vaccine."
"You will need to separate your powers and stay by her side constantly until she dies in order to suppress this symptom."
Ryuken Ishida jerked his head up, his eyes filled with struggle and pain.
He had already realized the problem.
Asking a Soul Reaper Captain to give up his powers to save an evil Quincy? That was simply impossible!
He looked at Masaki and opened his mouth, but found that the words 'let me do it' were stuck in his throat, unable to be voiced.
He knew very well that as a Quincy, he was completely incapable of providing the Soul Reaper power needed to neutralize the Hollow.
A profound sense of powerlessness rapidly spread through his heart.
'What should I do... Masaki...'
"I understand! I'll do it!"
A resonant voice shattered the silence.
Isshin Shiba untied his Captain's haori and casually tossed it onto the floor.
"You made it sound way too complicated! It just means giving up my Soul Reaper powers and protecting her for the rest of her life, right? Then let's hurry up and get to it! What a waste of time!"
"Soul Reaper... do you even know what this means?" Ryuken asked through gritted teeth. "You will lose everything... your seat, your power, your pride as a Soul Reaper..."
"Do you really have no lingering attachments to the Soul Society?" Kisuke Urahara also asked curiously.
"How could I not! I have plenty!" Isshin laughed heartily, turning to look at the groaning Masaki in pain. "But, if I just stand by and watch my savior die right in front of me without doing anything, the me of tomorrow would definitely laugh at the me of today!"
'This guy...' Ryuken Ishida froze, completely caught off guard by his answer.
Kisuke Urahara looked at Isshin and bowed slightly, a trace of respect showing in his eyes. "As expected of the head of the Shiba clan. Such magnanimity is truly admirable... In that case, I would like Captain Shiba to see an example."
He turned around, walked to one side of the Japanese-style room, and slid open a wooden door.
Isshin Shiba saw that Squad Member Asuka was lying on the tatami mats with his eyes tightly shut.
His breathing was even but heavy, and his body exhibited a strange sense of stiffness.
"His current state shares a similar concept with the upcoming treatment plan."
Kisuke Urahara pointed at Asuka, his tone flat. "To save his life, I also stuffed his soul into a special Gigai."
"However, the young man was a bit unappreciative, so I knocked him out..."
"This Gigai will suppress and disperse his original power, turning him completely into a 'human'. Perhaps only in this way will his soul, which is on the verge of shattering, avoid completely collapsing."
"And the method to save this Quincy lady is exactly the same."
Urahara turned his head, looking directly into Isshin's eyes. "You will enter the same type of Gigai, except you will bind the Quincy lady... together with your own soul."
"You will become a human, just like this young man."
Isshin Shiba looked at Asuka.
He indeed could no longer feel any trace of Spiritual Power from him.
"What's with that? You made it sound so scary..." Isshin smiled. His face, which usually wore a playful grin, was now filled with an open and honorable candor. "Doesn't sound too bad! Let's do it!"
"...Then please enter the Gigai."
Within Masaki's inner world.
It was a wasteland shrouded in a pitch-black rainstorm.
A massive rift tore through the sky, and a pure white Hollow wearing a horned mask let out a mournful roar.
Its sharp claws dug deep into the center of the earth, attempting to devour the entire world.
'Where is this? Am I going to die?' Masaki looked at the giant Hollow in bewilderment.
'Someone, save me...'
The massive maw slowly descended to swallow her.
"Hey, big guy."
A familiar voice rang out from behind Masaki, and she felt herself being lifted up.
"This girl's future has already been reserved by me. So, would you mind stepping aside?"
Isshin Shiba's figure appeared amidst the torrential rain.
"Ah—! It's the Mr. Soul Reaper from that day!" Masaki exclaimed.
"Yo, I'm here to protect you."
Isshin held Masaki's body close, turning his head to give her a radiant smile.
Roar—!!!
Seeing the sudden appearance of Isshin Shiba, the phantom of the Menos let out a deafening roar.
"Although I'd love to chat with you a bit longer, it seems we don't have the time right now."
Isshin's gaze instantly became as sharp as a blade.
He gripped Engetsu, and all the Spiritual Pressure in his body frantically condensed toward the blade at this moment.
"I probably won't be able to use this anymore... Consider this strike a parting gift to you!"
Isshin shifted his footing and twisted his body, his feet shattering the wasteland of Masaki's inner world as his Zanpakuto carved out a perfect arc—
"Getsuga Tensho—!!!"
In an instant, a crescent-shaped slash massive enough to span the sky howled forth!
It was Spiritual Pressure condensed to its absolute limit; it was Isshin Shiba's final swan song as a Soul Reaper.
In the real world, Masaki's tightly furrowed brows finally relaxed, and a smile appeared on her face.
Isshin slumped onto the ground, panting heavily.
Standing guard nearby, Ryuken Ishida looked at Isshin's back, which remained as tall and steadfast as a mountain despite the complete absence of Spiritual Power.
He suddenly realized something.
Masaki had already found where she belonged.