Outside the barrier, Unohana, Shunsui, and Ukitake paced restlessly, their gazes fixed on the mysterious sealed space before them.
Inside, Captain-Commander Yamamoto was drawing upon every last trace of his reiatsu, desperately resisting the terrifying power of the Solar Star.
He'd prepared himself as thoroughly as possible, yet only after confronting that vast torrent of solar power did he realize how badly he'd underestimated it.
The instant the raging energy surged into Ryūjin Jakka, an overwhelming pressure crashed down on Yamamoto like a collapsing mountain.
It felt as though he'd been thrown directly into a blazing furnace.
Every inch of his body seemed ready to ignite, and the suffocating heat was almost beyond endurance.
Ryūjin Jakka might have been praised as the strongest fire-type Zanpakutō, but even its flames looked painfully fragile before the true power of the sun.
The Zanpakutō spirit, whose soul was linked directly with Yamamoto's, was being mercilessly scorched by the True Solar Flame, its agonized roars echoing through their connection.
"AAARGH!"
A heart-wrenching cry tore from Yamamoto's throat.
The unbearable pain traveled through the Zanpakutō in his hand and flooded every part of his body. Even a man as powerful as him could no longer endure it in silence.
All he could do was clench his teeth and release more reiatsu, desperately forcing it against the increasingly violent True Solar Flame in an attempt to lessen the burning agony.
"Yama-jii!"
Kazuma's heart tightened at the terrible sight before him.
Yamamoto's entire body had been charred black.
His clothing hung from him in scorched tatters, and the aura spilling from his body had become dangerously unstable.
He was clearly reaching his limit.
At that critical moment, Kazuma immediately gathered star power within himself.
Brilliant starlight condensed in his palm, forming a dazzling sphere.
One infusion would heal Yamamoto's injuries and help him suppress the rampaging solar energy.
"Brat! This is my battle!"
Just as Kazuma prepared to intervene, Yamamoto forced out a thunderous shout.
"I do not require your assistance! If I cannot endure even this much power, then I will gladly let it burn me to ashes!"
The True Solar Flame had roasted him until he resembled an enormous cooked lobster, yet he still fought against the pressure and spoke with unbroken resolve.
Even Kazuma couldn't help being moved by the sheer force of his will.
"Remember this!"
Yamamoto looked at Kazuma one final time.
"If I truly fail to overcome this power, then the Gotei 13 will be yours to protect from now on!"
With those words, he closed his eyes and gathered every fragment of concentration he possessed, devoting himself entirely to the battle against the surging solar force.
Reiatsu poured from Yamamoto's body like burning fire, crashing repeatedly against the scorching power of the sun.
He fought with everything he had, but the True Solar Flame gradually forced him into a losing position.
"That stubborn old man…"
Kazuma's anxiety rose with every passing moment, but he respected Yamamoto's decision and didn't interfere.
His fists stayed tightly clenched as he watched without blinking.
The moment Yamamoto's life was truly in danger, Kazuma would save him regardless of what the old man wanted.
Time crawled beneath the suffocating tension.
Every second felt unbearably long.
The struggle continued, but Yamamoto's breathing had become labored, while the reiatsu within his body steadily weakened.
He couldn't maintain the confrontation for much longer.
Then the True Solar Flame, which already held an overwhelming advantage, suddenly erupted.
The blazing fire swallowed Yamamoto completely and formed an enormous sphere around him.
He'd become a burning human torch, and his situation was now truly desperate.
Another few seconds might be enough to reduce him completely to ash, bringing the terrifying contest to an end with his defeat.
"RAAAARGH!"
At the very moment death closed in and the True Solar Flame prepared to consume him, Yamamoto unleashed the final remnants of reiatsu hidden in the depths of his body.
He was no longer trying to survive.
He intended to drag the solar fire down with him.
Yet at that instant, the True Solar Flame — until then completely dominant — was somehow suppressed, as though it had met an opponent it could no longer overpower.
Kazuma, who'd been watching every change in the battle, clearly sensed the vast solar energy begin intertwining with Yamamoto's own power.
The two forces flowed together, gradually merging without the slightest flaw until they became one.
The power of the Solar Star had transformed completely into strength belonging solely to Yamamoto.
At the same time, Ryūjin Jakka underwent a tremendous transformation.
The already formidable blade erupted with greater fire than ever before.
The flames burning along it were no longer ordinary fire.
They had become the purest and most tyrannical True Solar Flame.
The greatest change, however, was Yamamoto himself.
The boundless solar power washed through his body and granted him a new life, ushering in the second spring Kazuma had promised.
Reborn from the flames, Yamamoto shed the exhausted appearance of a withered old man and returned to the vigorous form of his middle years.
The legendary Demon of the Sword, who'd once towered over all of Soul Society, had returned!
"Congratulations, Yama-jii."
Kazuma stared at him with undisguised excitement and joy.
He quickly removed his own captain's haori and carefully offered it to Yamamoto.
At the moment, the Captain-Commander looked rather disheveled — and more than a little indecent.
The True Solar Flame had been so fierce that it had completely burned away everything he'd been wearing.
Yamamoto now stood utterly naked, looking like an exhibitionist who'd wandered into the First Division courtyard.
Even so, his straight-backed posture and overwhelming presence hadn't diminished in the slightest.
If anything, the lack of clothing only added a certain wild, untamed ferocity to his appearance.
In truth, Yamamoto hadn't overcome the violent solar power through strength alone.
At the final moment, the will of the Solar Star had acknowledged him.
He'd abandoned every trace of fear and hesitation, confronting the sun with absolute resolve and a genuine willingness to die alongside it.
The Solar Star's will had sensed the unwavering conviction and fearless courage buried within his heart.
Once it accepted him, everything else followed naturally.
"So this is power beyond that of a Shinigami…"
Yamamoto slowly clenched one fist.
He could clearly feel the extraordinary power washing through and remaking his body.
At the same time, the spiritual power within him had begun undergoing a subtle transformation.
He could sense the change, but he didn't yet understand what it truly meant.