The Traveling Frog and Aizen's Ambition

Life after returning to Soul Society had become unbearably dull for Higashi Shuuichi.

Most of the Shinigami he once knew were now dead—claimed by time, war, or the quiet decay of relevance during his decade-long absence.

Those who survived were either fugitives in the World of the Living or people Shuuichi couldn't openly associate with—not if he didn't want to anger Tsunayashiro Kamihara.

So in the stillness of his new life, Shuuichi found amusement in an odd habit—daily checking in on the "Traveling Frog" he'd left behind in the Human World. A constructed being. A fabricated soul.

He'd named it: Tōno Takuya.

Though a bit dim-witted when left to act without Shuuichi's direct control—thanks to the constraints of imagination when it came to crafting autonomous behavior—Takuya still adhered strictly to the mission coded into him:

Find other Quincy in the World of the Living. Preferably pure-blooded ones named Kurosaki or Ishida. Learn their techniques. Master their powers.

Day One: Sunny.

Takuya left Osaka in search of Quincy allies. Got lost. Circled back by nightfall.

Day Two: Rainy.

Tried again. Confident this time. Ended up in the same spot. Again.

Day Three: Overcast.

Tried to take a bus. Didn't have money. Convinced the driver with… other methods.

Day Five: Sunny.

Finally arrived in Tokyo. Retrieved his katana from the bus driver's neck. Waved him off with a smile. He did a good deed today!

Day Six: Still sunny.

Takuya was arrested. No idea why. The bus driver from yesterday was there too. Strange—he looked very upset. Probably angry at the unfair police.

Day Seven: Cloudy.

Takuya broke out of jail. Couldn't use Quincy techniques yet, but his innate Schrift ability—carved into him—let him imagine and conjure a key. Easy.

Day Eight: Got arrested again.

Didn't even do anything this time. Just walking down the street. Why did the police keep targeting him?

Day Thirteen:

Human police had increased security. Takuya waited. Then a Hollow appeared. Chaos broke out.

He escaped.

The Hollow was slain—not by Shinigami, but by two Quincy.

They recognized him as one of their own. Pureblood.

Their names?

Kurosaki Yūki and his wife, Kurosaki Mai.

Day Twenty-Four:

Takuya moved in with the Kurosakis in Tokyo. Began rigorous Quincy training.

Created from Yhwach's body and infused with his core blood, powered by the Soul King's twin eyes, Takuya's potential was monstrous.

Within ten days, he mastered nearly all foundational techniques.

Switching between Blut Vene and Blut Arterie became instinctual.

Even the dreaded Ransōtengai—the Quincy's most difficult skill—took him only three days to perfect.

Kurosaki Yūki called him a once-in-a-millennium prodigy, a potential future King of Quincy.

Though Takuya often caught Kurosaki Mai watching him with a strange, pitying look.

Day Twenty-Nine:

Takuya revealed he knew Nagazawa Satomi.

Mai was shocked. Their bond deepened.

Day Thirty-Seven:

Takuya had just woken up to train again.

Then... an Arrancar arrived.

It was monstrous—eight tubes jammed into its back, a respirator masking half its face.

It appeared before Kurosaki Yūki and Mai.

At the exact same time, deep in Soul Society, Shuuichi awoke—and immediately seized control of Takuya's consciousness.

This was bad.

During this era, Aizen's fusion experiments had yielded mediocre results—boosting spiritual pressure limits in lower-tier Captains like Shuuichi, but failing to break the chains of Shinigami mortality.

Which meant Aizen was still focused on fusing Shinigami and Hollow power. And the control he exercised over Hueco Mundo was absolute.

No Arrancar moved without his permission.

So for one to appear now?

It meant Aizen was taking Shuuichi's words seriously. He was preparing for the Quincies.

So much for dismissing Yhwach with that smug grin, Shuuichi thought, a laugh in his throat.

He did have feelings for Yūki and Mai—not just because of their link to Nagazawa Satomi, and not just because they bore the name Kurosaki.

But because they had trained Takuya.

Tolerated his idiocy.

Guided him, even as he bumbled through misfortune after misfortune.

And now they were being beaten within an inch of their lives.

Yes, Yūki was a pureblood Quincy, but the era of Quincy glory was long past.

With Yhwach in slumber, most Quincy were shadows of their former power.

Yūki? Smart. Not strong.

No match for even a Vice-Captain-level Shinigami.

Certainly not an Arrancar.

Which made it all worse—Shuuichi couldn't intervene.

His true body remained in Soul Society.

Even if he could reach the Human World in time, there was no logical reason to act.

And Takuya, while strong, had limits.

Shuuichi watched as the Arrancar toyed with the Kurosakis.

They could have been killed dozens of times already. But weren't.

Why?

Because it wasn't here to kill. Not yet.

Shuuichi crouched, a grin breaking across his face.

He raised his hand, palm up.

If Takuya's Schrift "I" had a flaw, it was this:

It could only manifest things that should exist in the future.

The only reason Takuya could exist at all was because the idea of a Quincy born from Yhwach's body already existed in a possible future.

For most people, this ability was trash—if you couldn't imagine the future, you couldn't conjure it.

But for Shuuichi?

He knew the future better than anyone alive.

"Fly, Mokushō Drone Swarm."

Tiny owl-shaped drones burst from his palm, dozens at once, each no larger than a nightingale.

Within minutes, a 3D map of the surrounding area unfolded across Shuuichi's consciousness.

And among them, stood the man himself—Aizen Sōsuke.

"Looks like these strange things in the sky are your doing?"

Aizen hovered midair, one drone in his hand, wings still twitching.

He was surprised.

But not shocked.

It made sense, in hindsight.

He eyed the drone with clinical curiosity.

"And what's this little toy, stranger?"

Shuuichi smiled, bright as dawn.

"Yes, Lord Aizen!"

Aizen's brow twitched.

"...'Lord Aizen'? You know me?"

Only now did he turn, truly looking at the unfamiliar Quincy before him.

Young. Handsome. But unfamiliar.

And Aizen never forgot faces.

"Ah, I mentioned it last time, briefly," Shuuichi said. "You may have been distracted. Something about you dying in the future?"

He shrugged, casual.

"I said I gained something unexpected from that fabricated future. This Quincy power... is part of that."

No lies. No reason to lie.

Aizen wasn't the enemy. Not now.

If anything, Shuuichi might soon need his Hōgyoku to fuse new Soul King fragments into Takuya's body.

Because Urahara?

Far too unpredictable.

And Mayuri?

God only knows when his soul fusion research would finish.

So why hide it?

Better to be honest.

"Hmm... I see. This is your prize from that imaginary future, is it? Quincy power suits you well~"

Aizen's smile widened.

His eyes, bright with amusement, shimmered with a dangerous light.

The pieces clicked into place.

A Shinigami who'd broken his limits.

A follower growing stronger than he could predict.

And the idea came to him, unbidden:

What if Higashi Shuuichi broke the chains of death before even he did?

Aizen's heart leapt.

It was thrilling. Maddening.

From a disposable pawn with average spiritual limits, Shuuichi had risen—again and again—shattering every chain meant to bind him.

"Interesting... So very interesting..."

Shuuichi tilted his head. Aizen had tossed the drone aside, talking to himself, laughing softly.

He didn't understand.

But inside Aizen?

There was joy.

Not arrogance. Not condescension.

Joy.

He'd once thought that beyond Yamamoto, no challenge remained. That he'd be alone atop the mountain.

Now Yamamoto was fading.

And Urahara, clever as he was, still bored him.

But Shuuichi?

Shuuichi brought him three gifts:

He brought Aizen to the Great Spirit Book Gallery, where he learned of the Soul King and the Royal Guard.

He brought back knowledge of the future, of a Quincy king named Yhwach, who would one day try to destroy the world.

And now... he himself, walking proof that limits can be broken.

Even now, weak as he still was, Shuuichi's will never wavered.

He kept marching forward.

Step by step. Unstoppable.

One day... could he even surpass Aizen himself?

"Ahahaha... this world..."

Aizen laughed aloud now, voice echoing through the sky.

"...just keeps getting more interesting."