I'm in Bleach, starting with Unlimited Blade Works.

To cover up the darkness surrounding the birth of the first Zanpakuto, the Central 46 issued a peculiar order—no two identical Zanpakuto are allowed to exist in the same era within Soul Society.

This is because the abilities of the Zanpakuto that Asauchi created are incredibly diverse, and no two souls are exactly alike. Therefore, it is impossible for two Zanpakuto to be exactly the same.

However, the original batch of "strongest" Zanpakuto could choose their own suitable masters. As long as there was a certain compatibility between them, these Zanpakuto would respond to the Shinigami and become their Zanpakuto.

If two identical Zanpakuto appear in the same era, the truth that "Zanpakuto are born from the souls of Shinigami, are born with Shinigami, and perish with them" will be shattered.

In order to prevent the reputation of "Sword God" Nimaiya Oetsu from being damaged, the nobles of Seireitei would absolutely not allow such a situation to occur.

If people were to find out about the existence of this world, Captain Erin would have absolutely no place in Soul Society.

but……

After looking at the swords in this world, Aizen knew that such a situation was almost impossible.

Even without using the Zanpakuto that appeared in the hands of the Shinigami of this era in Soul Society, there are still a large number of powerful Zanpakuto waiting for that man to use.

However, Aizen still couldn't understand it when he saw the nine Zanpakuto flying out.

Why does this world even have Zanpakuto for Hollows?

Is it possible that Captain Erin can create any weapon in this world?

……

Two vice-captain level Zanpakuto, four captain level Zanpakuto, and three century-old captain level Zanpakuto further increased Erin's spiritual pressure.

Currently, in the entire Bleach world, the only swords that can significantly increase Erin's spiritual pressure are probably the Zanpakuto of the Zero Division.

Therefore, Erin doesn't spend much time on the lottery every day now.

More often than not, they rely on their existing sword-making experience to create the weapons they remember.

Any weapon that Erin can remember is at least a Zanpakuto of the Seat Rank or higher, and the improvement it brings to Erin is much faster than winning a lottery.

Aizen, who was sealed and hung on the cross, watched as Erin created one Zanpakuto after another.

Each time a Zanpakuto is created, Captain Erin's spiritual pressure increases slightly.

This terrifying rate of improvement was even faster than the speed at which he reached the limit of a Shinigami with the help of the Hogyoku.

Moreover, having made no progress at the limit of the Shinigami for many years, he could only repeatedly experiment with the Hollowfication of the Shinigami to complete the Hogyoku in his hands, using the power of the Hogyoku to break through the limit of the Shinigami.

However, the spiritual pressure emanating from Erin had long exceeded the limits of a Shinigami.

It's as if Captain Erin doesn't have any so-called "bottleneck" at all.

In fact, it does.

In the entire world of Death Gods, the upper limit of cultivation has been locked; the limit of Death Gods is the strongest realm that living beings can reach.

Even if one breaks through this limit using the power of the King Key, Zanpakuto, or Sacred Symbol, the difference in spiritual pressure won't be significant. Often, the outcome of a battle still depends on the compatibility of the two sides' abilities.

There are only three people in this world who can continue to improve after breaking through the limits of death.

Yhwach, Hyosube Ichibei, and Erin.

The Spirit King doesn't count.

The Spirit King was conceived by the will of the world and was born at his peak.

For over a million years, the Soul King has been weakened by the Tsunayo family, but even so, the Soul King, now turned into a human pig, is still the strongest being in the Bleach world.

Even a wisp of will can make the world move in the future it foresees.

Yhwach, the progenitor of the Quincy, can activate "Sanctification" at any time to reclaim all Quincy power to strengthen himself, as long as Quincy exist in this world.

Furthermore, as the "son of the Soul King," Yhwach is also able to absorb the Soul King's power for his own use.

It can be said that as long as Quincy exist in this world, Yhwach's strength can be raised to a level comparable to that of the Soul King.

Unfortunately, a thousand years ago, the Empire of Light was severely damaged by the Gotei 13 led by Yamamoto Genryusai Shigekuni. Yhwach, whose power was partially sealed by Hyosube Ichibei using the right arm of the Soul King, was almost killed by Yamamoto Genryusai Shigekuni and fled into the shadows of Seireitei. He has only recently regained consciousness and his strength has not yet recovered.

Hyosube Ichibei is essentially "black." As long as the concept of "black" exists in the world, he can absorb power from all the "black" in the world.

However, Hyosube Ichibei has existed for over a million years, and his power has reached its peak.

He is truly the strongest being below the Spirit King.

Furthermore, with his power, he could even use his abilities to name the "Spirit King Candidate" as "Spirit King," granting him the power of a Spirit King.

Of course, for Hyosube Ichibei, the so-called "power of the Soul King" was nothing more than a "wedge to stabilize the world."

Having immense power is ultimately used to stabilize the world; it does not refer solely to the original "Spirit King".

Similarly, Erin's essence is "sword," and he can gather the power of all "swords" in the world into one, allowing him to reach the level of Hyoninbe Ichibei.

Moreover, the "swords" in the Bleach world can elevate Erin to a level comparable to Ichibei Hyosube, but those swords outside the Bleach world can allow Erin to go even further, surpassing Ichibei Hyosube, and even surpassing the Soul King.

Of course, since Erin has not yet unleashed the full potential of all the swords in Unlimited Blade Works, he is still some distance from Ichibei Hyosube.

But at the very least, Erin is now significantly ahead of the others.

He has already reached the same level as Yhwach and Hyosube Ichibei.

Aizen cannot yet comprehend Erin's level of understanding, but that does not mean he cannot see that there is already a dimensional gap between Erin and himself and the others.

In other words, he felt that Erin, in some ways, had already entered the realm of "gods".

Although Erin felt that his current strength was enough to rank him among the top three in the Bleach world, he would not underestimate the others in the Bleach world because of that.

Especially scientists.

Kisuke Urahara counts as half.

Mayuri Kurotsuchi, counts as one.

After being banished from Soul Society, Kisuke Urahara did invent some things, but he focused more on improving his strength.

However, judging from its performance in the Thousand-Year Blood War, Mayuri Kurotsuchi's inventions were more useful than Kisuke Urahara's.

Therefore, Erin's fear of Kisuke Urahara can only be considered half-hearted.

Mayuri Kurotsuchi was the person he feared most, besides Yhwach and Hyosube Ichibei.

Mayuri Kurotsuchi is a pure scientist; even in battle, he modifies his Zanpakuto into an "automatic" parrying Zanpakuto.

Kisuke Urahara is different. His Zanpakuto, Kannon Kai Benihime Kai, has the ability to transform all things. As a result, he uses his Zanpakuto more to create things rather than inventing many powerful auxiliary items.

It can be said that in the field of invention and creation, Mayuri Kurotsuchi has surpassed Kisuke Urahara in the more than 100 years since Urahara left.

The spiritual pressure amplifier and spiritual pressure suppressor invented by Mayuri Kurotsuchi are absolutely extraordinary things, and Erin is envious of them.

If one fully understands the principles of these two things and forges them into a Zanpakuto, the improvement to Erin's strength will be no less than that of identifying or creating the strongest Zanpakuto.

If given the chance, Erin wants to get in touch with Mayuri Kurotsuchi's Zanpakuto after the Thousand-Year Blood War, and achieve synchronization with it. Just like understanding Aizen's experiences over the years, he wants to absorb Mayuri's experience and gain a sufficient understanding of spiritual pressure amplifiers and spiritual pressure suppressors, so that he can use the abilities of these two things to create a powerful Zanpakuto.

……

After Erin finished his work for the day, he looked up at Aizen Sousuke, who was sealed in wooden shackles.

"Yo, Captain Aizen, it's been a long time."

"Ha, Captain Erin, I used to think that I was the one who was the most well hidden in the entire Seireitei."

"But compared to Captain Erin, I am still too superficial."

Before encountering Erin, Aizen was proud.

When Aizen broke through to the level of a captain who had been in the army for a hundred years, he came into contact with the Soul King's will and learned the Soul King's secrets.

The Spirit King is an omnipotent god and should rightfully stand in heaven.

However, it was betrayed by the five noble families and ultimately became a "wedge" in the stabilization of the world.

Therefore, after obtaining Kisuke Urahara's half of the Hogyoku, Aizen said, "No one has ever stood in the sky from the beginning, not you, not me, not even a god."

Although this was also the Spirit King's own choice, sacrificing himself for the world, such a "god" can no longer be considered "standing in the heavens".

"The vacancy of the throne of heaven is about to end. From now on, I will stand at the top." This is Aizen declaring to the Shinigami that he will fulfill the Soul King's will and achieve his wishes, and then he will become the new "god".

Of course, his "god" is definitely different from the "god" of the Spirit King.

The Soul King was betrayed by his five followers, so Aizen never trusted anyone.

He only believes in his own strength!

Unfortunately, Erin, who was not affected by Aizen's Kyoka Suigetsu ability, remained unaffected within the entire Seireitei.

To eliminate the uncertain factor of Erin, Aizen Sousuke arranged a series of plans, the best outcome of which would be to kill Erin if they were successfully implemented.

In the worst-case scenario, Erin could be banished from Soul Society.

However, Erin did not give him that opportunity.

After the first attempt, Erin went directly to his door and sealed him within Unlimited Blade Works.

"Indeed, I knew who you were from the first time I saw you."

"Over the years, I haven't tried to stop any of your actions."

"As long as you don't provoke me, I'm happy to watch you grow step by step."

"I've told you before that I have no interest in you as you are now. I'll come back to kill you when you reach your peak."

"However, you have crossed my bottom line. No matter how much I want to fight you at your peak, I cannot gamble on the people I care about not harming them."

On Sword Hill, Erin did not hide anything from Aizen, whom he had already sealed away.

In any case, barring any unforeseen circumstances, Aizen Sousuke's future is already sealed by his own will.

"Then all of this was just me being delusional."

"So, Captain Erin has never really taken me seriously..."

Aizen didn't doubt Erin's words.

Having fallen to this point, Captain Erin had no reason to lie to himself.

"No, it's not that I don't take you seriously, but rather that you are not yet worthy of my attention."

Erin shook his head and corrected Aizen Sousuke's words: "What I value is the you who will achieve great things in the future, not the you who is still as weak as an infant in my eyes now."

"To be valued so highly by Captain Erin, Aizen is extremely fortunate."

"However, Captain Erin, with your strength, you've probably already come into contact with 'that,' so why do you accept this world so calmly?"

After witnessing Erin's true power, this was something Aizen Sousuke couldn't understand.