Invitation from the Zero Squad?  

The essence of the leader of the Royal Guard, Ichibē Hyōsube, is "black". All "black" in the world is his power.

During his battle with Yhwach a hundred years later, Yhwach's "Almighty" only took away Ichibē's "black" for an instant. The black in the world then returned to Ichibē, allowing him to regain his power.

Now, Ailin was similar to Ichibē Hyōsube. However, while Ichibē's essence was "black", Ailin's essence was the "sword".

All swords in the world were Ailin's power. Spanning the past and future, as long as the concept of the "sword" existed in the world of Soul Reapers, Ailin's power could not be taken away by Yhwach.

Sensing the "swords" gradually gathering in his innate boundary field, Ailin nodded in satisfaction.

Finally, his innate boundary field had matured. It would now search for more swords on its own, making him stronger.

Aside from collecting all the "swords" in the world, after fusing with the "King's Treasury", Ailin's Unlimited Blade Works also greatly enhanced its ability to project and throw weapons.

After all, the "King's Treasury" itself possessed the means to attack enemies by throwing weapons like arrows.

After merging with Ailin's Zanpakutō, it completely covered Unlimited Blade Works' projectile method.

Originally, the weapons projected by Ailin's innate boundary field could only open a spatial aperture in one direction to throw out "swords".

However, the "King's Treasury" could open spatial apertures in all 360 degrees without blind spots, allowing for a saturated bombardment of the enemy.

Furthermore, while Unlimited Blade Works' projectile speed was fixed, the "King's Treasury's" projectile speed was related to its own level and the level of the weapon.

The higher the "King's Treasury's" level, the faster it could throw weapons and the greater their power.

The higher a weapon's level, the faster it would be thrown, and naturally, the greater its power.

If ranked using the Type-Moon scale, among the Zanpakutō currently in Ailin's innate boundary field, the ordinary and elite Soul Reapers' Zanpakutō were D-rank weapons numbering over ten thousand.

The Seated Officers' Zanpakutō were C-rank weapons numbering over five hundred.

The Vice-Captains' Zanpakutō were B-rank weapons numbering around three hundred.

The Captains' Shikai-releasing Zanpakutō were A-rank weapons numbering under one hundred.

And the Zanpakutō known as the "strongest" were A++ rank weapons numbering around thirty.

So far, Ailin only had one "EX" ranked weapon - Avalon. This was enough to raise the "King's Treasury's" level to A-rank.

In other words, when Ailin used the "King's Treasury" to throw weapons now, each strike would not fall below the full power of a Captain-class combatant.

Using Seated Officers' Zanpakutō, the projectile's power could match that of a Captain's Shikai release.

Following this logic, using Vice-Captains' Zanpakutō could match a Captain's Bankai attack.

Using Captains' Zanpakutō could match the Bankai of a hundred-year veteran Captain.

Using the "strongest" Zanpakutō could match Head-Captain Yamamoto's Bankai.

"Now, I only want to say one thing - who else is there?"

Pulling his now fully golden Zanpakutō out of the Sword Hill, Ailin let out an arrogant shout. After venting for a while, he thrust his Zanpakutō back into the Sword Hill and regained his calm.

Indeed, with his current Zanpakutō's ability, he could be called "invincible" in the world of Soul Reapers. However, this awakened even greater ambitions in Ailin.

He still wanted to experience more worlds. After becoming invincible in power, he would continue to pursue "invincibility" in other aspects.

Whether it was swordsmanship, Shunpo, hand-to-hand combat, or Kidō, he would cultivate them all to the pinnacle and then break through that pinnacle!

***

Slowly opening his eyes, Ailin maintained his current motionless posture. His reiatsu's breakthrough made him feel that everything besides himself was exceedingly fragile.

Even the slightest movement made him feel like the entire Seireitei could be destroyed. Now, Ailin could especially empathize with what Sōsuke Aizen had once said:

"Stepping over ants without crushing them requires exquisite control."

Ailin felt that if he wanted to kill an ant right now, he might end up destroying the entire mountain the ant was on. Fortunately, he had never slacked in his cultivation.

After some time, Ailin gained complete control over his surging reiatsu, fully locking it within his body.

After all, reiatsu that had broken through the limits of Soul Reapers was far too powerful.

If Ailin released his reiatsu now, it might cause all three realms to tremble.

However, controlling his reiatsu was one thing, but his body enhanced by that tremendous reiatsu was not so easy to control.

Ailin estimated that even without using sword techniques, the shockwaves from his casual sword swings could shatter a mountain.

***

"Huh? The old man Yamamoto is looking for me?"

The next day, as Ailin was moving about in the courtyard, he noticed a Hell Butterfly flying towards him. Extending his hand, after the Hell Butterfly landed on his finger, Ailin read the information it carried.

"I just broke through yesterday, and the old man Yamamoto is looking for me today. Could he have noticed that I surpassed the limits of Soul Reapers?"

Ailin was puzzled.

Genryūsai Shigekuni Yamamoto was also an expert who had broken through the reiatsu limits of Soul Reapers. Otherwise, he would not be known as the "Strongest Soul Reaper in a Thousand Years".

However, Yamamoto's breakthrough occurred in his Bankai state, where his surging reiatsu forcibly elevated him to the next realm.

In his base state, Yamamoto's reiatsu strength was still confined within the limits of Soul Reapers.

Ailin's breakthrough occurred in his innate boundary field, a completely different space from the Soul Society. Ailin did not believe that Yamamoto could detect his breakthrough unless he intentionally leaked his reiatsu.

Unless the old man Yamamoto released his Bankai...

"Never mind, I'll just go ask him what he wants."

After shaking his head, Ailin did not hesitate further and flashed towards the First Division's direction.

"Well, well, Vice-Captain Sasakibe, it's you waiting for me again this time."

The moment Ailin's figure appeared behind Chōjirō Sasakibe and greeted him, Sasakibe's whole body trembled, his immense reiatsu almost bursting forth before instantly being suppressed by Ailin.

'This, this is impossible? When did Captain Ailin arrive? I didn't even notice? And my reiatsu, it was so easily suppressed? Captain Ailin, you're so strong!'

Sasakibe's shock was evident on his face. In his view, perhaps only the teacher could overpower Captain Ailin in the entire Seireitei.

The idea that Ailin had already surpassed Head-Captain Yamamoto never crossed Sasakibe's mind.

"Captain Ailin, the Head-Captain has been waiting for you for a while now. Please come with me."

Although stunned, Sasakibe was not one to make trouble. All he cared about was whether he could share Yamamoto's burden and properly fulfill his responsibilities.

So even though he realized Ailin's strength far exceeded his own, Sasakibe felt no envy, but rather happiness that Ailin could better assist the Head-Captain.

"Head-Captain, Captain Ailin has arrived."

"Hmm, Chōjirō, you may leave. I have matters to discuss with Captain Ailin."

"Yes, Head-Captain."

Watching Sasakibe leave, Ailin became even more convinced that the old man Yamamoto had something significant to discuss by summoning him.

After all, to Genryūsai Shigekuni Yamamoto, the person he trusted most in the entire Seireitei was undoubtedly Chōjirō Sasakibe.

Even his two disciples, Jūshirō Ukitake and Shunsui Kyōraku, were not as trusted as Sasakibe.

Sasakibe had followed Yamamoto for over a thousand years as his aide. Although titled as an aide, Yamamoto viewed him as a disciple and valued him greatly.

After forming the Thirteen Court Guard Squads, Yamamoto had hoped for Sasakibe to become a Captain to showcase his talents. Unfortunately, Sasakibe refused every time. He only wished to serve under Yamamoto and had no desire to become a Captain.

Even when convening Captains' meetings, Yamamoto had never asked Sasakibe to leave. But today, summoning Ailin privately and asking Sasakibe to leave was the first time Ailin had seen.

After Sasakibe left, Yamamoto finally looked at Ailin, his deep voice carrying the majesty of the Strongest Soul Reaper in a Thousand Years as he asked, "Captain Ailin, have you perhaps created something recently?"

"Huh?"

Hearing Yamamoto's question, Ailin was puzzled.

"Head-Captain Yamamoto, I've just been cultivating in the Kuchiki Manor these days. Aside from forging a few Zanpakutō, I haven't done anything else. Could the Zanpakutō I created have some issue?"

"No..."

Yamamoto glanced at Ailin and confirmed he was not lying before continuing without reservation.

"This morning, I received a message from the Zero Squad. They wish to invite you to join the Zero Squad and have asked me to inquire about your opinion.

If you are willing to join the Zero Squad, they will send other members to welcome you and take you to the Soul Palace to become a member guarding the Soul King."

Yamamoto asked Ailin because he knew how difficult it was to become a member of the Zero Squad.

There were only two ways to join the Zero Squad...