Following behind Unohana, descending step by step along the stairs into the Central Great Underground Prison, Kensei felt like a death row inmate heading for the execution grounds. Though he probably wouldn't actually die, a sparring match with Sister Hana was practically the same thing.
Back when his spiritual pressure hadn't grown to this level, Sister Hana might have known restraint. But now... Kensei wasn't so sure.
"Almost there, Kensei."
Unohana's voice echoed through the empty stairwell. It was gentle and pleasant, carrying a strange maternal quality—yet Kensei still instinctively shrunk his neck.
"Haha... Sister Hana, you certainly picked a... um... secluded spot."
Kensei laughed dryly. Here, you could do more than just spar—you could commit murder and no one would ever know.
"The Seireitei doesn't have many places where we can truly cut loose. Ordinary training grounds probably couldn't withstand both our spiritual pressures."
Unohana continued her unhurried descent, a hint of amusement in her voice.
They arrived at the deepest part of the Central Great Underground Prison—Muken. It was so quiet here you could hear a hair drop.
"Here will do." Unohana stopped in the center and turned, her face wearing the same gentle smile as always. "It took some effort to secure this place, so please, don't hold back."
Kensei rested his hand on Kūkon's hilt, staring at the Fourth Division Captain across from him, silently cursing the entire Tsunayashiro clan.
Oh, and Old Man Yama too. If that old geezer hadn't recalled him, he'd still be in Hueco Mundo right now, living a decadent life of luxury and debauchery!
Old Man Yama, I curse you—may you never find another student as filial as me.
"Begin, Kensei. Let me see how much you've grown since your time in Hueco Mundo."
The moment Unohana finished speaking, her Zanpakutō was already drawn, slicing through a dangerous arc.
Kensei's blade answered in kind, barely managing to block what seemed like a simple strike.
"Impressive for a thousand-year veteran Captain."
That single exchange told Kensei everything—this was the purest, most refined slash, honed over a millennium.
"Oh my. Is Kensei suggesting I'm getting old?"
Kensei's hand trembled at her words. Though her voice remained as warm as a spring breeze, he caught an undertone.
The next instant, Unohana's blade trajectory shifted. The edge grazed past Kensei's cheek, shearing off a few strands of hair.
"Oh dear, how clumsy of me." Unohana retreated a few steps, her smile still tender. "I have lived rather long. My aim isn't what it used to be."
Kensei's mouth twitched. If he explained now that he hadn't meant it that way, would it save his life?
Unohana vanished again.
If her earlier attacks carried temptation, from now on, every strike held undisguised ferocity.
Unohana moved like flowing water. As the first Kenpachi, she needed no flashy techniques—only sword strikes capable of taking lives.
Kensei had to focus completely. He had plenty of special tricks, but ending the fight that way would surely displease Sister Hana. For now, he could only rely on his swordsmanship to defend and counter.
Kūkon traced arcs through the air. In the dim Muken, only the cold gleam of reflected blades and the sparks of clashing steel illuminated the darkness.
"Not bad."
After a fierce exchange, Unohana temporarily ceased pursuit. Her voice held both admiration... and dissatisfaction.
"Still not enough, Kensei. You know as well as I do—this level of fighting barely counts as warming up."
"Show me the power you truly mastered in Hueco Mundo."
Unohana tilted her head slightly, her eyes gleaming with the light of a predator sizing up its prey. Her flowing hair drifted gently upward.
Her fingers traced along her blade. Shadows from Muken played across her face, transforming the usually gentle Captain into something resembling a demon.
Kensei took a deep breath. His fingers brushed the wounds Sister Hana had left on his body, using Kaidō to heal them. Now he understood—she hadn't brought him here for a simple spar. This was something far more primal: combat.
"Then, Sister Hana... please watch closely."
Kensei swept his hand across his face. The white mask with blue patterns fit against his skin. His spiritual pressure turned furious, brimming with aggression.
The instant Kensei's mask completed, the gentle mask on Unohana Retsu's face shattered as well.
What emerged now was pure joy. The battle lust burning in her eyes was so intense it nearly spilled forth.
"Yes—this is what I wanted to see!"
Unohana's voice trembled with extreme excitement. Though she now wore the mantle of Healing Captain, the Zanpakutō in her hand transformed utterly into a blade thirsting for blood.
A thousand years ago, Soul Society's great villain—the first Kenpachi, Unohana Yachiru—awakened once more.
Two figures collided, separated, and collided again in Muken's timeless depths. The metallic ring of clashing blades became a furious drumbeat. Shockwaves from their attacks shattered pillars throughout the prison.
A gash on Kensei's left shoulder laid bare the bone beneath. Countless wounds, large and small, covered his body. Blood dyed his Shihakushō crimson.
But Unohana fared little better. Her Shihakushō hung in tatters. A deep wound across her abdomen refused to close.
"Just as I thought... my long wait was not in vain."
Unohana touched her fingertips to her wounds, collecting a smear of blood. She gazed at the crimson stain, then extended her tongue and licked it clean. Her smile grew radiant.
From beneath his Hollowfication mask, Kensei's voice emerged with an electronic echo. "Never would have guessed you had this side to you, Sister Hana."
"The feeling is mutual."
After a brief respite, both vanished once more. Though both had mastered advanced Kaidō, neither chose to heal now. Instead, they seemed to savor the sting.
Their wounds multiplied with each clash. Blood painted Muken's floor, adding fresh color to this sunless domain.
In Muken, where dawn never broke, they lost all sense of time. They simply swung their blades, again and again.
None could say how long passed before they finally stopped.
"Haah... Sister Hana... no rematch for a while, right?"
Kensei's Hollowfication mask had shattered and disappeared. Blood loss left his face pale.
Unohana slowly sheathed her Zanpakutō. A pity her Shikai wasn't combat-oriented; her Bankai would be overkill, robbing the battle of further joy.
She wiped blood from the corner of her mouth and leaned against Kensei, who had also collapsed from exhaustion. "I'd love to continue, but neither of us has strength left. If we pushed further... one of us might not walk out. Though I admit, that prospect does hold a certain appeal."
"Sister Hana... jokes like that are better left unsaid."
Kensei's mouth twitched. If only he could unleash his Bankai properly—he wouldn't have let her get so arrogant.
"Oh? Are you sure?" Unohana chuckled softly, reverting to her usual gentle demeanor. "Still... today brought rare joy. Thank you, Kensei."
"You're welcome."
Kensei tilted his head back. Maybe he should just move to Hueco Mundo permanently. Were there any normal Shinigami left in the Seireitei?
Sigh. All Old Man Yama's fault for letting Soul Society sink into such twisted customs. It would take the most normal person—himself—to set things right.
For the sake of justice, Old Man Yama, abdicate already.