Explanation of Sousuke Aizen's current power

Key conclusions

• Shunsui makes a deal with Aizen to help the Gotei 13 fight the Ihwach for much needed help.
• Aizen, a post-Hogyoku fusion, is the most powerful Shinigami besides Ichigo, with incredible abilities.
• Aizen's immense strength, Kidou prowess, and immortality make him invincible and indestructible.

In the last episode Bleach: The Thousand Year Blood Warthe newly appointed captain commander of Gotei 13, Shunsui Kyoraku, finds himself in an underground prison beneath Squad 1's barracks, Muken. There, while his best friend Captain Ukitake makes a deal with the Mimigaha God to save the Soul Society, Shunsui makes a deal with the devil Sosuke Aizen. Kyoraku speaks to Aizen shortly before releasing him from the seal to ask him to help the Gotei 13 in their battle with Ihwah. Shunsui knows that there is no one as powerful as Aizen except Ichigo and they need all the help they can get.

It has been two years since Aizen was sealed after an epic battle against Dangai Ichigo at the hands of Kisuke Urahara. And yet, he's still a being on a completely different level than anyone on the battlefield besides Ichigo and Ihwach. While Aizen has always been a level above a normal Shinigami, his fusion with Hagyoku has given him an incredible power that surpasses anyone else in the world Bleach.

Sosuke Aizen before and after Hogyoku

An anomaly, a being beyond any other

When Sousuke Aizen was born, the balance of souls was disturbed. Aizen is an anomaly in every sense of the word. It should not exist. Already at birth, he was a being far superior to other Shinigami. But he knew how to hide it, so he entered Shinigami Academy and joined the Gotei 13, serving as the vice-captain of Squad 5 under Shinji Hiroko. After his Hollowfication experiments ruined the lives of the Shinigami who became Vizored, Aizen became the captain of Squad 5, with Momo Hinamori later as his vice-captain. Using his Zanpakutou, Kyouka Suigetsu, he faked his death and betrayed the Gotei 13 by killing every member of the Central 46. He retrieved his Hogyouku and fled to Hueco Mundo with Captains Jin Ichimaru and Kaname Tosen.

From the beginning, no one stood in the heavens. Not you, not me, not even the gods. However, that unbearable vacuum is over. From now on I will stand in the heavens.

During the battle with the Gotei 13 in the Karakura Fake City arc, Aizen easily defeated all the members of the squad except the former Captain Commander Yamamoto. All this without using the complex Kidou techniques he is an expert at, or even his Bankai if he has one. The only enemy Aizen saw close to him in terms of power was Yamamoto, and he created an experimental Arrancar called Wunderweiss Margera to deal with him.

He then begins to transform into a transcendent being, merging with the Hogyoku. He fights Urahara, Ishin Kurosaki, and Yoruichi Shihouin with ease, all while transforming. Once it reaches a new stage of evolution, its power becomes so incredible that it completely obliterates any human that comes close to it. After being betrayed by Jin Ichimaru, he evolves again, and when fighting the newly evolved Ichigo, he achieves a final, terrifying transformation. He was hit by Ichigo's Final Getsuga Tenshou: Mugetsu. And still he survives. He is sealed by Urahara and the new Central Court 46 sentences him to 18,800 years of imprisonment in Muken.

There, Aizen remained fused with the Hogyoku, quietly improving his powers, completely discarding the physical form of his Zanpakutou, Kyōko Suigetsu. When Ihwach went to him during the First Quincy Invasion, he was able to use his Zanpakutou powers just by looking at him. Aizen became one with his Zanpakuto and Hogyoku.

Aizen's current power

Invincible and overwhelming

Due to his fusion with Hogyoku and his transcendent evolution, Sōsuke Aizen is the most powerful Shinigami to ever exist, aside from Ichigo Kurosaki, a completely different case. Aizen can easily manifest his powers without even releasing his Shikai. His Kidou skill also increased. He is able to cast extremely powerful spells on Kid without casting spells. Such as Hadou 99: Kurohitsugi (Black Box) and Hadou 99: Goryuutenmetsu (Five Whirling Dragons of Destruction), one of the most powerful techniques in Bleach.

In addition to his overwhelming strength, he is effectively immortal and indestructible. He can take any injury and survive. Aizen had to be struck by God's power to sustain significant damage or even be on the brink of death. Thanks to Hogyoku, Aizen's already abnormal strength tripled. As Muken's guard went up to Aizen to hold him down, his hands crumbled as soon as he got close. Aizen's spiritual pressure is so dense and powerful that anyone who gets close to him will die instantly. The seals don't erase his spirit pressure, they just keep it close to him.

I have to say… You are a really funny person. Would I like some fresh air, you ask? Will this be a breath of fresh air for the Soul Society crushed by Yhwach?

Shunsui also removed only three seals on Aizen: the mouth, left eye, and ankles. This means that most of Aizen's body is still sealed away. This is only part of his full power. Yhwach previously revealed that Aizen is one of the special threats of the war. This is due to Aizen's almost infinite power and spiritual pressure. He is invincible, fused with Hagyoku, fused with his Zanpakutou and an enhanced version of his Transcendent Evolution.

• 

  Bleach: The Thousand Year Blood War

• 

  Based on the Shounen fighting manga by Tite Kubo, Bleach centers on Ichigo, a high school student drawn into the world of Soul Reapers. The original anime ended in 2012, but it was revived in 2022.