Eighteen Years Later.
Seireitei, a remote, uninhabited mountain.
Toshiro sat cross-legged, eyes closed, focused on training.
Within the Inner World's ice crystal palace.
Toshiro sat upon the ice crystal throne. Above him, the Ice Dragon Pearl rotated steadily, streams of Divine Power continuously flowing into him, being refined and absorbed.
When Toshiro first attempted to absorb Divine Power, he was cautious, absorbing only one strand at a time, requiring his full effort even for that single strand.
Now, Divine Power poured in continuously, yet Toshiro refined and absorbed it effortlessly, which is a world of difference.
Over these eighteen years, Toshiro diligently refined and absorbed Divine Power from the pearl. Though his Reiatsu's total 'quantity' hadn't increased much, and his realm remained at the pinnacle beyond Captain-level, its 'quality' began changing, gradually acquiring a deep, almost mystical, divine attribute. His Reiatsu now carried hints of Divine Power.
Moreover, after years of refinement, Toshiro felt his Reiatsu had reached a critical threshold… not just in quantity, but also in quality. He sensed that breaking through this threshold would allow him to transcend the beyond Captain-level limits and reach the Demi-god level.
Thus, this time, Toshiro prepared to attempt a full breakthrough to the Demi-god level.
As Divine Power from the pearl continuously poured into him, Toshiro felt the bottleneck restraining him begin to waver, needing only a final push to break.
But that final gap stubbornly blocked him. As time passed, the wavering bottleneck started stabilizing again.
Seeing this, the previously calm Toshiro grew anxious. Although failure now meant future attempts, the saying 'first time with full vigor, second time weakened, third time exhausted' held true. If he didn't break through decisively now, subsequent attempts would grow increasingly difficult.
Moreover, time waited for no one. Toshiro couldn't recall the exact start date of the original plot, but remembered the approximate time. He estimated only one or two years remained.
Without a breakthrough, even if he could counter Kyoka Suigetsu, lacking strength surpassing Aizen's would prevent a true confrontation.
Once the plot began, he'd be relegated to a supporting role, clinging to the protagonist Ichigo's coattails.
'Damn it! I was once sworn brothers with Shiba Isshin and far stronger than him. If I end up following his son around, he'd definitely laugh at me if we ever meet again!'
Thinking this, Toshiro resolved to break through to Demi-god level in one go. Instantly, he increased the rate of drawing Divine Power from the pearl.
If initially the flow was like a small stream, now it became a surging river. Divine Power poured into Toshiro like raging floodwaters.
"Hmph!"
Toshiro grunted in pain. The influx overwhelmed his refinement speed. Unrefined Divine Power rampaged through his body, damaging internal organs.
"Damn it!"
Gritting his teeth against the pain, Toshiro frantically mobilized every ounce of power, operating at overload to refine and absorb the Divine Power.
As Toshiro fought desperately, the stabilizing bottleneck began wavering again, as if about to shatter.
"Haah!" Toshiro roared, disregarding potential bodily harm, further increasing his refinement speed.
Crack!
The wavering bottleneck developed fissures.
Bang!
The barrier restraining Toshiro shattered completely.
Instantly, Toshiro felt as if a heavy shackle had been removed, his body feeling weightless.
Boom!
His Reiatsu, nearly stagnant at the pinnacle of beyond Captain-level, surged rapidly. Not only did the 'quantity' increase, but the 'quality' also improved severalfold. Toshiro could feel that upon breaking through to Demi-god level, his Reiatsu's nature had begun transforming, acquiring some Divine Power attributes.
Moreover, he sensed his abilities starting to change. Immediately, he focused on perceiving the changes post-breakthrough.
However, engrossed in exploring his newfound power, Toshiro didn't notice the immense pressure radiating from him, spreading in all directions.
Crackle, crackle-!!
Wherever Toshiro's pressure passed, all matter froze, transforming into an icy world. This [Frozen Kingdom] continued expanding, threatening to engulf the entire Seireitei, even the Soul Society.
…
1st Division, Duty Room.
The moment Toshiro broke through and his power erupted, Yamamoto, handling official business, sensed it immediately.
"This Reiatsu... Toshiro's?"
"Such immense pressure... Could it be… has he also reached that step?" Yamamoto murmured to himself.
Setting aside his work, Yamamoto headed towards the source of the Reiatsu.
5th Division.
"Hitsugaya Toshiro... So you've finally reached this step too," Aizen muttered to himself.
"It seems another troublesome figure like Yamamoto Genryusai has emerged," Aizen frowned.
But then he smiled. "However, that makes things more interesting, doesn't it?"
"After all, if plans succeed too easily, where's the challenge?"
Meanwhile, all Shinigami in the Seireitei sensed Toshiro's overwhelmingly powerful Reiatsu.
"What immense Reiatsu! What's happening?" Ordinary Shinigami wondered, puzzled.