"The research on Shinigamization has made progress. You'll be the perfect test subject."
"As for your son, Kakashi, I'll take good care of him. He's a brilliant child—he'll surely become an excellent assistant of mine."
"If all goes according to plan, I'll become his foster father in three days. Don't you think that's a beautiful thing?"
'—!!!!!!'
Within a glass containment cell, a shattered blue humanoid form struggled violently, eyes burning with rage. The world around him was filled with test tubes, preserved organs, and pulsating machinery.
And amid the endless mechanical hum stood Aizen Sōsuke—dressed in a spotless white haori, calmly writing as though performing calligraphy under the pale glow of sterile light. His every movement exuded serenity, like moonlight in the midst of madness.
Sensing the fury directed at him, Aizen adjusted his glasses, smiling gently. With his hands tucked into his sleeves, he stepped closer to the containment unit.
"Good afternoon, Hatake Sakumo, Jōnin of Konoha. Forgive the humble state of my laboratory—it's not quite befitting a guest of your stature."
'...'
Sakumo glared at him, trembling with fury.
The man before him—so polite, so refined—was the very embodiment of his deepest fear realized.
"You—if you so much as touch my son—Aizen, I'll kill you!"
"How interesting," Aizen mused softly. "It seems the souls of suicides often lose their restraint. Comparing you now to when you were alive… the difference is fascinating. The living Sakumo would have never reacted so impulsively."
He pushed his glasses again, the reflection flashing like a blade of light.
The captured father's reflection was cast in the cold gleam of that lens—transparent, fragile, and utterly powerless.
"Magnificent," Aizen whispered. "No matter how often one studies the soul, it never ceases to inspire awe. Every spirit reveals a unique truth if examined correctly."
'Kill… you…!'
"Ah, still resisting? Remarkable. Even in a purely spiritual state, you can sustain vocalization through sheer willpower. But don't fret, Sakumo-kun. You can't hurt me… nor can you change anything."
He turned back to the console, fingers deftly adjusting switches and levers. The room filled with a low, ominous hum.
"I hold no ill intentions," he continued gently.
"I truly wish to teach him. He's a prodigy, and… I do get lonely working alone."
'You're… not to be trusted…'
"Trust is irrelevant to truth," Aizen replied calmly. "He will become my foster son—that much is fact. And all of this only came to be because you chose death. Tell me, Sakumo, when you took your own life, did you think of your son? Only now, after death, do you regret it? How human. People always realize what's precious only after it's gone."
'...'
Sakumo's spiritual form froze.
He hadn't thought about it.
Kakashi—barely six years old, about to graduate the Academy.
His mother long dead in childbirth. His father—a supposed traitor who chose suicide over shame.
What kind of world would that child now face? What kind of life could he possibly live?
Yes… dying to prove his innocence had given him peace—
but for Kakashi, it was only the beginning of loneliness.
Sakumo fell silent within the containment field.
Aizen, however, did not allow him time for grief. His hand pressed another switch.
A surge of pale blue energy exploded around the chamber. The soul screamed—a soundless, piercing shriek—as ethereal sparks tore through his very being.
Calmly, Aizen observed the monitors, comparing readings between two screens, taking notes like a teacher lecturing mid-experiment.
"This is a valuable opportunity, Sakumo-kun. You were a wise man, so you deserve to understand your situation."
"The Art of Spiritual Transformation, Natural Energy, and Chakra—there is a conversion mechanism between the three."
"To manifest a pure soul in the physical world isn't impossible. One only needs a reflective medium—something that bridges the gap between spirit and nature. And that medium isn't chakra… but will."
"Fascinating, isn't it? When self-awareness reaches a certain intensity, it can influence natural energy directly. Chakra merely responds to the pull—but it's will that commands it. My research began with that truth."
"Perception of the world and of oneself," Aizen continued, "that is the essence of what makes us unique. To desire is to act. Even the ancients could peer through something unseeable, isn't that right, Sakumo-kun?"
'...'
Through the pain, through the blue lightning shredding his essence, Sakumo listened. Beneath the agony, his mind—trained as a shinobi—clung to focus. He analyzed, deduced, and realized:
Aizen wasn't speaking idly.
He was explaining something vital.
But every time he tried to think, the light intensified, compressing him like molten metal hammered in a forge. His soul's impurities—especially the traces of chakra—were crushed and burned away.
Aizen, meanwhile, spoke on—calm, gentle, serene.
"Kato Dan. The wielder of the Ghost Transformation Jutsu," Aizen said softly. "I was deeply saddened by his death… You remember him, don't you? No one in Konoha held greater research potential."
"He died a meaningless death—sacrificed to duty, killed by incompetents. His dreams passed to others. But what of it? Kato Dan is dead. And his beloved? Skilled only in medical ninjutsu. A pity."
"Human bodies are merely puppets of chakra, after all—flesh molded by energy."
"But a thousand years ago, things were different. Natural energy, souls, spiritual transformation, chakra… I've completed the first step. I've broken the boundary between body and soul. Now, I only need proof."
"Hypothesis must meet verification—and that's where you come in, Sakumo-kun. If you can endure, I'm sure Kakashi will be proud."
He smiled faintly.
"Come now. I'm on your side. In truth, I'm probably the person who least wants you to disappear."
'AIZEN—SŌSUK—KE!!!'
Aizen sighed. "Still not calm? What a shame. Your erasure will mark a failed path—and that would be tragic. Do survive, Sakumo-kun."
He pressed another button.
Light engulfed the chamber—so brilliant that even the soul's scream was swallowed.
And then—silence.
...
Aizen verified the readings, set the device on automated control, and left the lab without a backward glance.
As he stepped into the dim corridor, a familiar voice greeted him from the shadows.
"Still playing the villain, are you, Aizen?"
"Oh my," he said smoothly, adjusting his glasses. "To see you here of all places… what brings you out of rest?"
Leaning against the wall stood a tall man with long, pale hair—elegant, calm, yet with an aura of defiance.
"Your soul materialization experiments remain unstable," Aizen noted gently.
"Appearing so suddenly risks assimilation by natural energy or chakra. I'd advise rest."
"I felt fine," the man replied mildly. "Just thought I'd stretch my legs, maybe read a bit. You don't mind, do you?"
"You sensed a new soul arrive, didn't you?"
Aizen's smile deepened, genuine and warm—almost too sincere.
"You're still as poor a liar as ever, Dan-kun. So gentle. You felt your old comrade's presence and came to warn me, didn't you?"
"…I can't deny that."
There he stood—Kato Dan, the former Konoha Jōnin who had mastered the Ghost Transformation Jutsu, once famed as one of Konoha's most gifted.
A man who should have died from grievous injuries on the battlefield—now a soul preserved by Aizen's forbidden art.
He sighed softly and walked up beside Aizen, standing shoulder to shoulder.
"I just don't like the methods you use," he said quietly.
And so, like old friends, the dead and the deceiver walked side by side down the dim corridor—
one radiating serene warmth,
the other, silent disapproval.
Both bathed in the cold, indifferent light of Aizen's laboratory.