Gin Ichimaru

Hueco Mundo, Las Noches.

Aizen was currently conducting experiments with the Hogyoku here.

Because the quantity of Soul King fragments was still insufficient, Aizen had not yet begun research into the Arrancarization of Adjuchas-level Menos.

Although the King of Hueco Mundo had lent him 100 battle-hardened Adjuchas to experiment with at his leisure—with more available if those weren't enough—Aizen was currently still focused on the Shinigami Hollowfication experiments he was more familiar with.

This Hollowfication process involved injecting a Hollow's soul into a Shinigami's body to shatter the boundary between the two souls; it was a trial meant to destroy the original subject and sublimate them into a higher-level soul.

This was something Aizen wanted to be able to achieve himself in the future, but since his mastery of this technique was still lacking, he would not use it on himself.

What could be confirmed for now was that only those with Reiatsu at the level of a lieutenant or higher could temporarily withstand the destruction of their own boundaries caused by Hollowfication.

However, a sustained "Hollowfied" state would cause the two souls to gradually fuse into one, turning the subject into a mindless monster and causing the boundary between their own Reiatsu and the external Reishi to vanish, ultimately resulting in "soul suicide"!

This was a difficult problem that even Aizen had not solved... yet it had been solved by Urahara Kisuke.

The principle of the solution was to inject a soul opposite to that of a Hollow—namely, a human soul—thereby allowing the balance that had collapsed due to the loss of boundaries to reach a new equilibrium.

That was how the Visored had been saved.

But this caused the boundaries to reappear, which contradicted Aizen's goal of constantly elevating his own limits.

Therefore, the conclusion was that more experiments were needed to pursue the perfect answer.

Inside the barrier before Aizen, a female Shinigami whose face was already completely enveloped by a Hollow mask was struggling incessantly. Although this one-armed female Shinigami had clearly lost her own will, her combat methods were quite violent.

She even unleashed a Cero, yet she still could not break the cage that imprisoned her.

After some time, the female Shinigami's form suddenly expanded and then exploded.

"A failure!"

Aizen collected the shattered soul; as expected, the souls of the Shinigami and the Hollow could no longer be separated!

Tosen Kaname took the soul and recorded the transformations that had occurred within it.

Tosen Kaname's need for Hollowfication was no less than Aizen's, so he was deeply concerned with the results of every experiment.

After all, Hollowfication also represented the potential to obtain powerful strength.

Tosen Kaname did not need to reach the extreme requirements Aizen sought; he only needed enough power to cut down evil.

However, although this experiment was important to them all, it was not something they could perform indefinitely.

Because Shinigami with lieutenant-level Reiatsu could not be found just anywhere.

Each one required some effort to acquire.

In comparison, the Hollow side was much easier.

Every Gillian possessed a Reiatsu of the fifth rank.

After all, they were formed by the mutual devouring of hundreds of Hollows, their Reiatsu condensed into one.

Moreover, compared to Shinigami, the sign of a Hollow breaking its boundaries was much more obvious.

That was the shattering of the Hollow mask, which was why they were called Arrancar!

Contrary to Hollowfication, artificially controlling the Arrancarization of a Hollow required the injection of a Shinigami soul.

Aizen's Hogyoku contained a vast number of Shinigami souls; while it was still short of supplying a large-scale Arrancarization of Adjuchas, it was more than enough if he used Hollows that were not yet Menos for his experiments.

Aizen had not yet fully occupied Hueco Mundo; he was in a cooperative relationship with the King of Hueco Mundo, so he could not act as recklessly as he might have otherwise.

Furthermore, Aizen was certain that if he succeeded in changing the Soul Society, he would inevitably have to fight the King of Hueco Mundo in return!

A sound echoed beside Aizen as Gin Ichimaru appeared.

Aizen asked gently, "You've worked hard, Gin. Have you confirmed it?"

Gin Ichimaru's squinting eyes never opened; he simply smiled and nodded, saying, "Confirmed! Hueco Mundo and Hell have been at war for over a thousand years! More than a third of the land in Hueco Mundo right now was seized from Hell."

"That is truly remarkable." A white light glinted on Aizen's glasses. "What a truly capable King of Hueco Mundo!"

Tosen Kaname also felt an even deeper sense of irony.

Hueco Mundo had been engaged in a "just war" for over a thousand years, and the Soul Society hadn't even received word of it, let alone contested it.

A sense of disgust, a deep sense of disgust, appeared in Tosen Kaname's mind.

He even began to develop a certain sense of identification with Hueco Mundo.

Aizen's vigilance, however, only grew stronger because of this. "Prepare for the Arrancarization experiments! If we wish to overthrow the current Soul Society, the power of Hueco Mundo—even if it may be our enemy in the future—is a partner we must cooperate with for now!"

Tosen Kaname and Gin Ichimaru nodded simultaneously.

However, unlike Tosen Kaname's somewhat agitated movements, Gin Ichimaru remained very calm.

At least, he was calm on the surface.

The turmoil in his heart was hidden beneath his mask of a fake smile, so deep that even Aizen could not discern it.

Gin Ichimaru had just met the King of Hueco Mundo!

On his way back from the battlefield of Hell, the King of Hueco Mundo had seemingly been waiting for him there all along.

Furthermore, the King of Hueco Mundo only said one thing.

"I will help you retrieve the soul fragments Rangiku Matsumoto lost; in return, you work for me. How about it?"

Upon hearing these words, Gin Ichimaru's heart churned like a stormy sea.

Yet, Gin Ichimaru's expression did not change in the slightest.

He dared not reveal his emotions, for he feared this might be a fabrication created by Aizen's Kyōka Suigetsu.

However, the King of Hueco Mundo easily dispelled this thought by mentioning something Gin Ichimaru did not know yet, but could easily verify later without raising any suspicion.

The effect of Kyōka Suigetsu was not mere illusion, but complete hypnosis.

In reality, it was equivalent to Aizen providing the target of the hypnosis with a beginning and an end.

Aizen would not know the process or the various details in between; those had to be filled in by the target's own brain.

But it was impossible for the target to fill in details they had never seen before.

This way, he could verify later whether he was currently under the influence of Kyōka Suigetsu.

"If you have verified it and agree to my request."

"Then continue to follow Aizen's orders; do not make any changes without my instructions."

Having said this, the King of Hueco Mundo vanished from before Gin Ichimaru.

The complete absence of any reiatsu signature made Gin Ichimaru feel even more as if he were under the influence of Kyōka Suigetsu.

Yet, it was also highly likely that this was merely a lingering remnant of the past left behind by the King of Hueco Mundo using Past Reenactment.

The abilities of these two were things that even Gin Ichimaru, who excelled in direct combat, could not accurately grasp.

He truly could not grasp them!

But Gin Ichimaru's habitual mask of a fake smile never wavered.

He returned to Aizen's side with his usual composure.

He continued his actions, as if nothing had ever happened.