Regarding Gotei 13's name, should it be Genryūsai Shigekuni Yamamoto or Aizen? Isshin Shiba didn't care at first.
After all, he doesn't like Central 46 or Soul Society. Otherwise, he would not be able to settle down in this world in the future. Even if he regained his Shinigami power, as the head of the Shiba branch house, he still would not have returned to Soul Society, even then.
Regarding the authority of Gotei 13 and the ownership of Soul Society, between the Sōsuke brothers and Genryūsai Shigekuni Yamamoto, he personally prefers the former.
Otherwise, he would not have chosen to take part in the entire battle just now; no, he would have just watched a show.
From beginning to end, not even a trace of Reiatsu was used, let alone drawing the sword.
Only the Sōsuke brothers replaced Genryūsai Shigekuni Yamamoto, took over Gotei 13, and even took Soul Society into their hands. They were still not satisfied, and insisted on moving to Zenith, and even wanted to replace the Soul King. It was unacceptable to Shiba.
"Captain Isshin Shiba, can I understand that you are declaring war on us?"
Seeing Isshin Shiba put his hand on Zanpakutō's knife handle, Aiyan just smiled.
"That's right."
Isshin Shiba looked determined.
"Is it just you?"
Aizen shook his head and laughed, seemingly amused by Isshin Shiba's behavior.
"I am enough!" Isshin Shiba nodded wholeheartedly, without any intention of joking.
"Do you need me to help you recall the history of the Five Great Noble Families?"
"Soul King, you still choose to betray; a wedge between life and death, yet you choose to draw your sword against us.
"Or, in your eyes, the Soul King should exist in the form of a wedge, not a god who can step down from the throne."
Aiyan looked at Isshin Shiba with a half-smile.
"As a descendant, I cannot interfere with the will of our ancestors, nor can I stop it, but I can do what you say.
"Aiyan, give up this terrible thought and call it a day!"
"The safety of the Soul King is above all else and involves life and death in the three realms."
Isshin Shiba looked ugly, but couldn't refute.
As the head of the Shiba branch house, he also knows about the sordid past of his ancestors.
"Then you should have stood unswervingly on Genryūsai Shigekuni Yamamoto's side from the beginning.
"Although doing this won't increase your chances of winning much."
Aiyan nodded.
"Because I want to give you brothers a chance."
Isshin Shiba made a surprising statement:
"I have been a special teacher at Shinigami Academy for a hundred years, and have taught at least ten Shinigami. But in this long teaching career, I have never seen a Shinigami who is more outstanding than you two brothers, not even one. No."
"So, I am reluctant to destroy you two with my own hands."
"In the final analysis, this is what Seireitei owes you. The power of Soul Society fell into the hands of your brothers. It will be better than that of Genryūsai Shigekuni Yamamoto, and the guys in Central 46 will be in much better hands."
He looked around at Aiyan and spoke word by word.
"Captain Isshin Shiba, don't speak arrogantly; it will only make you look weak."
The corners of Aizen's lips curled up, and his voice revealed a hint of sarcasm.
"Listening to your tone, it seems to me that you think you are stronger than Genryūsai Shigekuni Yamamoto?"
Aiyan looked at Isshin Shiba with interest.
"If you understand it this way, it's true. I am indeed stronger than Genryūsai Shigekuni Yamamoto."
Isshin Shiba listened wholeheartedly and actually nodded, saying something that shocked Byakuya Kuchiki, Tousen Kaname and others at this moment.
The Shinigami present all looked at him with disbelief, as if they were looking at a delusional patient.
Even Kyoraku Shunsui and Jūshirō Ukitake were no exception.
They all saw with their own eyes how powerful Genryūsai Shigekuni Yamamoto was at full strength.
But such a Shinigami, who holds the Zanka no Tachi and has been as strong as the sun for thousands of years, was still defeated by Aiyan's Shikai. It is really difficult to understand where Isshin Shiba got the courage to say such arrogant words.
Especially looking at the opponent's posture, it is obvious that they are planning to fight two. Go alone and challenge Aiyan.
"Interesting."
Seeing this, Aizen stopped mocking his smile and became a little more hopeful.
He originally thought that the war would come to an end when Genryūsai Shigekuni Yamamoto died in battle, but he never thought that something unexpected would happen.
"Aiyan."
"Sōsuke."
"I ask you one last time: obey the Soul King, and Soul Society will be yours, or so."
Isshin Shiba didn't say anything more.
"In the new Three Realms, I have already prepared a place for you."
"Pity."
"Go ahead, Captain-Commander Genryūsai Shigekuni Yamamoto."
Aiyan looked at Isshin Shiba wholeheartedly and said nonchalantly.
"I think it's a pity.
"Soul King, and everything Soul Society.
"You already had it at your fingertips, but your brothers pushed it away."
After listening to Isshin Shiba, he pulled out Zanpakutō and cut off the last hesitation in his heart:
"Aiyan, you brothers, come on together!"
He held his Zanpakutō, pointing at Aiyan and Aizen.
"Don't be too arrogant, Isshin Shiba."
"You alone are not worthy of joining the people of Aiyan and Aizen."
"You're just the captain of the 10th Division, so let me help you settle it with my own hands."
Seeing that Isshin Shiba actually wanted to attack Aiyan, Tousen Kaname immediately pulled out the Zanpakutō, and then Shunpo stepped forward, holding the Zanpakutō straight towards Isshin Shiba's heart.
Facing Tousen Kaname's slash, Isshin Shiba didn't even look at him, not even at the Zanpakutō. He just raised his left hand and flicked his fingers.
Boom.
The powerful Reiatsu burst out, breaking the atmosphere, and knocked away the Zanpakutō that Tousen Kaname had slashed with.
"I see, it seems that I underestimated you."
Tousen Kaname rolled in the air and landed on the ground. The anger on his face subsided a little and was replaced by solemnity:
"Bankai: Suzumushi Tsuishiki: Enma Kōrogi."
In an instant, an elliptical barrier expanded, enveloping Isshin Shiba in it.
He felt his vision, hearing, taste, and Reiatsu consciousness leave him one by one; he looked at the dark surroundings. There was no fear or surprise on his face. Instead, he raised his Zanpakutō with one hand, found a random direction, and chopped it down with all his strength.
"Getsuga Tenshō!"
As the powerful Reiatsu rolled and surged, a round of azure sword pressure immediately burst out from the blade, like a huge crescent moon. With an unparalleled and proud attitude, it shot straight into the sky and instantly tore apart the ellipse in all directions.
Poof.
Amidst the sound of sharp blades slicing flesh, blood arrows sprayed out.
Tousen Kaname flew hundreds of meters away in the air, but Isshin Shiba steadied his body.
He covered the bone-deep knife wound on his chest with one hand, and his face was filled with disbelief.
"Oh?"
"I didn't even finish you off with one blow. It seems I underestimated you."
"Yes, you are no longer the student of Shinigami Academy in the past. You are just Getsuga Tenshō in a sealed state. It is indeed a bit difficult to deal with a captain-level Shinigami who uses Bankai."
Isshin Shiba glanced at Tousen Kaname and saw that Tousen Kaname was still standing. He was a little surprised at first, but he immediately reacted.
Tousen Kaname was no longer the Shinigami Academy student he remembered, but a genuine captain-level Shinigami.