Beyond the distant shores of space and time.
The seventh level of Soukaizan, which should have towered into the clouds and overlooked the entire colorful world, was currently shrouded in thick, dark clouds.
There were no stars, sun, or moon in the sky; only a suffocating storm of chaos roared above.
This was the source of all evil that had corrupted the entirety of Soukaizan—the domain of the King of the Demon World, Doakudar.
And in this desolate land that devoured even light itself, several figures stood firm against the oppressive pressure, gazing resolutely at the colossal Mashin before them.
One of them, a man with completely white hair and beard, was leaning on a tachi as if it were a walking stick, sizing up their opponent with absolute composure.
It was none other than Genryusai Yamamoto.
A mere few days was nothing but a fleeting moment for this Head Captain, who had lived for thousands of years and witnessed countless monumental changes in the Soul Society.
Yet, his experiences on Soukaizan over these past few days had stirred long-forgotten ripples in his ancient heart.
He still remembered the magma sea on the second level.
When he released Ryujin Jakka, fully prepared to reduce those bizarrely shaped new Menos and the entire mountain peak to ashes...
That human boy, Wataru Ikusabe, had recklessly thrown himself in front of his blade.
Those clear, pure eyes devoid of any ulterior motives, and that unwavering resolve to protect his friends despite his obvious fear...
...had caused Yamamoto to halt his void-severing blade at the very last second.
Through their subsequent conversations, Genryusai Yamamoto finally grasped the situation.
This vibrant yet heavily scarred world was not the one he knew. Those massive constructs were not Menos created by Aizen, but rather a special type of combat weapon unique to this realm.
More importantly, he learned that the boy before him, Wataru, was not a native of this world either, just like himself.
He was a savior summoned by the gods of this world from a place called the [Real World].
"A human from the World of the Living..."
After learning the truth, Genryusai Yamamoto had stared at the distant sky for a long time.
The arrogant ravings of that traitorous wretch, Aizen, atop Sokyoku Hill still echoed in his ears. He had to return to the Soul Society as soon as possible to stop Aizen's mad ambition of overturning the order of the Three Realms.
However, despite his immense strength, he had no idea how to get back.
The only apparent solution was to help this human boy save Soukaizan, and then use that dimension-crossing power to try and open a path back to the Soul Society.
Thus, the Supreme Commander of the Gotei 13 temporarily became a member of this small subjugation force.
The third level, the fourth level, the fifth level...
They advanced with unstoppable momentum.
The level guardians and powerful Mashin that should have forced Wataru and the others into bitter, desperate struggles...
...were as fragile as paper dolls in the hands of a child when faced with the combined efforts of Genryusai Yamamoto and Wataru, crumbling without a fight.
Ultimately, they carved a path through all obstacles and arrived before the King of the Demon World.
"Hahaha! You're finally here, little savior Wataru Ikusabe!"
At the center of the chaotic storm, a terrifying, colossal demonic shadow—seemingly forged from countless despairing souls and abyssal shadows—towered over the land.
Even though the Mashin mechas were already massive, they appeared incredibly tiny before this demonic shadow.
"Doakudar! Give me back my good heart, and return the peace that everyone lost!"
The final battle.
Wataru drew his sword and shouted furiously, summoning Ryujinmaru, determined to fight the Demon King before him to the bitter end.
Master Shibaraku, Torao, and the others also summoned their respective Mashin mechas, preparing to face this final battle alongside Wataru.
Only Head Captain Yamamoto and Himiko stood off to the side, making no immediate move to intervene.
"Give it back? Hahaha!" Doakudar laughed maniacally. At the center of the massive demonic shadow, a faintly glowing white orb slowly materialized. "Your good heart is the most delicious nourishment."
"Having lost your good heart, only anxiety and fear remain within you. What will you use to sever the darkness?"
Before his voice even faded, dozens of thick, destructive death beams shot out from Doakudar's massive body.
"Wataru, watch out!"
Piloting Jakomaru, Torao attempted to cleave through the death beams, but was instantly blown away by the terrifying impact.
The group immediately engaged Doakudar in a chaotic melee. Explosions and flames filled the space between heaven and earth, relentlessly battering everything on the ground.
Yet, whether it was Master Shibaraku, Suzume, or the newly reformed Dodo, none of them could harm Doakudar in the slightest.
"Certain Victory・Toryuken!"
Seizing an opening, Wataru let out a mighty shout.
The Sword of the Sword King on Ryujinmaru's back erupted with dazzling golden sword aura, slashing head-on toward Doakudar's body.
Clang—!!!
Unexpectedly, the usually unstoppable Toryuken couldn't advance a single inch upon striking Doakudar's armor!
'How can this be?!' Wataru thought in shock.
"It's useless! I am currently wearing the armor of justice." Doakudar's mocking voice echoed across the realm. "This is a product fused with your good heart. Any attack you make will be neutralized by its power."
"You will never be able to defeat me!"
"Damn it... Not even the Sword of the Sword King can cut through it..." Feeling the powerlessness transmitted through his hands, panic flashed in Wataru's eyes.
He subconsciously looked toward the old man who had been helping him all this time, but the man remained standing perfectly still, showing no intention of stepping in.
"Old man! Please, do something! That Doakudar's power is too great; Wataru can't break through that barrier at all!" Master Shibaraku pleaded loudly.
"Yeah! If you just go swish, you can definitely send that bad guy flying!" Himiko stomped her feet anxiously from the sidelines.
His grizzled beard dancing in the demonic aura, Yamamoto's withered hand merely rested quietly upon the hilt of his sword.
"I refuse."
"Why?!" Inside his cockpit, Torao wiped the blood from the corner of his mouth and shouted angrily, "You clearly have so much power! Are you just going to watch Wataru get killed?!"
Yamamoto looked up at Ryujinmaru battling in the sky, his gaze filled with trust and expectation.
He could indeed step in and assist with the battle immediately, and he certainly needed to hurry back to the Soul Society.
But he also understood that the true savior of this place was the boy before him, who had lost a piece of his good heart.
This was the bond and connection between Wataru Ikusabe and this world. If he couldn't rely on his own strength to achieve a personal breakthrough...
...then perhaps one day in the future, this place would face the exact same peril.
Beyond his identity as Head Captain, Yamamoto was also a teacher who had instructed countless Soul Reapers, the founder of the Shin'o Academy.
His style was known as Gen-ryu.
"Can a heart that was stolen by another, and requires begging for someone else's help to retrieve, still be called your own heart?"
Yamamoto's gaze pierced toward Ryujinmaru like a sharp sword. "Brat! If all you do when faced with an insurmountable crisis is hope for the pity of the strong, then you are unworthy of wielding the sword in your hands."
"Liberate your heart. Your good heart can never truly be taken away."
"In this abyss of despair, use your soul to reforge it!"
This stern reprimand, booming like thunder, caused even the lofty Doakudar to freeze for a moment.
"Hahaha! You're quite an interesting old fossil. You're just sending him to his death!"
"A human who has lost his good heart can't even overcome his own fear! What will he use to stand against the Demon World?!"
Doakudar abruptly opened his abyssal maw, transforming endless dark miasma into thick chains that tightly bound Ryujinmaru's limbs.
Intensely corrosive magical energy began to frantically destroy the mecha's armor, and a brilliant red light flared beneath the entire canopy of the sky.
"Uwaaaah—!"
Enduring agonizing pain, Wataru's body trembled violently from the shockwaves.
However, Genryusai Yamamoto's words had indeed ignited a forgotten corner deep within his heart.
'Reforge... a new one?'
Wataru struggled to lift his head. Through Ryujinmaru's eyes, he saw the figures of his friends.
There was Torao, desperately fending off the demonic aura for him; Master Shibaraku, recklessly trying to rush over to save him; and Suzume and Himiko, their eyes brimming with tears.
He recalled every little moment since he first set foot on the first level of Soukaizan.
The villagers who remained smiling despite being oppressed, the companions who were covered in wounds just to protect him...
"My good heart was indeed taken by you..."
Wataru slowly closed his eyes, no longer focusing on the glowing orb inside Doakudar's body.
Instead, he submerged all his consciousness deep into his own soul.
"But my feelings for everyone haven't disappeared! My desire to protect everyone, to protect this world—that feeling has never left me!"
"Likewise, everyone's hearts have always beaten alongside mine!"
"Even if it was stolen, as long as I still believe in my friends, as long as I haven't given up hope..."
"...the flame in my heart... will never go out!"
Vmm—!!!
At that very moment, Ryujinmaru, whose light had dimmed while being tightly constricted by the dark chains...
...suddenly erupted with a powerful and pure divine light from within.
"What?!" Doakudar's maniacal laughter came to an abrupt halt.
To his disbelief, he realized that the good hearts he had stolen from other humans—along with the one that originally belonged to Wataru—were beginning to tremble violently inside his body.
Then, with a sharp crack, they shattered on their own!
At the same time, his absolute defense, which was built upon those good hearts, began to crumble and shatter!
"How is this possible?! What did you do?!" Doakudar roared in a mix of shock and fury.