In the Bleach universe, the Bankai is the final and complete form of the Zanpakutō; it is the culmination of his training and for the Shinigami to obtain it, it is necessary to force the spirit of the Zanpakutō to materialize. Achieving Bankai is rare and even once obtained, it takes another ten years of minimum training to perfect its mastery, in most cases. A Bankai can be extremely powerful and thus extremely dangerous, which is why they are so intriguing. But, not all Bankai have been revealed in the series so far and Sōsuke Aizen’s Bankai is one of them.
In this article, we are going to talk about what Aizen’s Bankai could possibly be. Namely, we know that Aizen has mastered Bankai, that much is clear, but his Bankai has not been revealed, and as it stands, it is not going to be revealed, unless Kubo decides to change things a bit. While we wait for Kubo, we are going to discuss the theoretical possibilities surrounding Aizen’s Bankai.
Aizen’s Zanpakutō: Understanding Kyōka Suigetsu
Aizen is one of the most powerful characters in the Bleach universe. He is far stronger than most of the Captains of the 13 Divisions, themselves powerful fighters. He had no trouble defeating a coalition of four Captains and four Vizards single-handedly, showing that he is an exceptional fighter. It must be said that the monstrous strength of Aizen is accompanied by his Zanpakutō, Kyōka Suigetsu, which has a capacity for hypnosis.
All of this gives him a tactical advantage on the battlefield. In addition to these exceptional combat abilities, Aizen is a genius, whether perfecting his combat techniques or innovating new technologies. He is also a shrewd strategist, planning several moves ahead of his opponents, even if it means sacrificing his soldiers or even faking his own death.
Being born with great potential, Aizen has developed an inordinate arrogance that gives him a manipulative and defiant face, which pushes his enemies over the edge. Finally, Aizen also knows how to surround himself with the best soldiers. Gin Ichimaru, his second in command, is a bloodthirsty fighter (like Zaraki) and a once-a-decade genius (like Hitsugaya). Kaname Tōsen is the only fighter immune to his hypnosis power. And finally, he gathered the elite Hollows under his command into an army of Arrancars (which are Hollows with Shinigami powers), among which are the Espadas, themselves of the level of a Captain of the 13 Divisions.
As we have stated, Aizen’s Zanpakutō is one of the main reasons why he is such a dangerous foe. Why? Well, Kyōka Suigetsu has the unique ability to completely confuse its opponents, but before we explain that in detail, let us tell you a bit about the sword. As the name of Kyōka Suigetsu (Japanese: 鏡花水月, literally: Mirror Flower, Water Moon) suggests, it uses deceptive properties; the moon reflected in the water and the flower seen in the mirror are things that can be seen but not touched.
This is derived from a Chinese proverb, which is supposed to show people that wishes and dreams cannot always be fulfilled so that people do not allow themselves to be led into temptation. As seen in Episode 211, Kyōka Suigetsu’s blade has a crescent moon just above the hilt. Presumably, this change only occurs when Aizen releases his Zanpakutō. Also, it is probably related to the Suigetsu (water moon) part of the name.
Aizen initially introduced his Zanpakutō as a water-based one to his fellow Gotei 13 members; he even called all the Lieutenants to show it to them collectively. Little did they know that this was actually part of his menacing plan. Namely, Kyōka Suigetsu, regardless of its name, is not a water-based Zanpakutō, it is actually an illusion-based Zanpakutō.
The Shikai release command for Kyōka Suigetsu is “Shatter.” It has the property of putting anyone who sees the blade of Kyōka Suigetsu under complete hypnosis (Kanzen Saimin). After that, Aizen can make her see, hear, and feel anything he wants. According to Aizen, hypnosis is unbreakable even if the person knows they have been hypnotized. The only ways to avoid being hypnotized are either to touch the blade before complete hypnosis or not to see Kyōga Suigetsu’s Shikai, making blind Kaname Tōsen immune to Kyōka Suigetsu’s powers.
The hypnosis appears to be permanent, or at least extremely long-lasting, as Aizen used the effect on nearly all of the Gotei 13’s individuals during a ceremonial release of his zanpakutō years before he faked his death. While the illusions created by Kyōka Suigetsu are quite good, they are not perfect as Captain Retsu Unohana noticed that something was wrong with Aizen’s “corpse”; however, she was unable to figure out what until she saw Aizen alive.
The hypnotic abilities are also useful in battle because Aizen can use his Zanpakutō’s ability to create an image of himself and thus fool him. While the opponent concentrates on the counterpart and does not notice Aizen at all, he can attack his opponent without any problems. Aizen had deceived all the Shinigami by making Hinamori look like himself, so Hitsugaya attacked the deception, seriously injuring Momo in the process. To everyone involved except Ichigo, it looked like Aizen was being attacked.
The gist of it is that Aizen’s Shikai is one of the most powerful ones in the whole series. Similar to Shinji’s Shikai, the Kyōka Suigetsu creates very powerful illusions that allow Aizen to do whatever he wants with those he has hypnotized with Kanzen Saimin. The duration of the hypnosis also seems to be limitless, as the Visored remained under its influence even after more than a century.
The freighting fact about it is that even Yhwach was not immune to these illusions (and while using The Almighty!), but Aizen did not know how he was affected by it like he usually does, but that is a result of Yhwach’s immense powers, rather than the Shikai’s weakness. And with that, we can conclude this part of the article.
Why hasn’t Aizen’s Bankai been revealed in Bleach?
Most Bankai of the Gotei 13 have been introduced at one point or another. Byakuya’s was, for example, introduced early in the story, whereas Kenpachi’s Bankai was introduced just before the end of the story, but most have been. Notable exceptions include the 13th Division’s Captain, Jūshirō Ukitake, former 2nd Division Captain, Yoruichi Shihōin, former 7th Division Captain, Love Aikawa, and – Sōsuke Aizen (Shinji’s and Hisagi’s Bankai have been shown in the light novel).
Now, we don’t know why Kubo hasn’t shown us, or at least described, the Bankai of these characters, but while Yoruichi and Love are somewhat understandable (the former never fought with the sword, while the latter had a small role in the story overall), Ukitake and Aizen remain a mystery, especially since there was space to introduce both (Ukitake’s Bankai has been hinted at in the Brave Souls video game, but that is not can).
Aizen’s Bankai could easily have been introduced during the Quincy arc; it could’ve been introduced as part of the Arrancar Saga as well, but we can understand that Aizen’s narcissism clouded his judgment then, as he was sure that he could defeat all of his opponents without his Bankai. The issue is that no one even suggested the possibility of Aizen activating his Bankai, but let us say that the decision not to introduce it during the Arrancar Saga made sense. The Quincy Arc did not make much sense, especially since Aizen’s Bankai would’ve been a very useful weapon in fighting Yhwach. So, why haven’t we seen it?
Well, the only in-universe reason that actually makes sense is that Aizen’s Bankai is simply too powerful to properly fit the lore. That is a theory we had about Ukitake’s Bankai as well, as Ukitake can absorb any non-physical attack and return it to the opponent, making him practically untouchable. As the Bankai amplifies the powers of the Shikai, it is understandable how such a powerful Shikai could become an invincible Bankai. Sure, it would have a weakness, and it would not be literally invincible, but it might have been a way out that was simply too easy; the Bankai could’ve possibly defeated Yhwach easily, and that would not make sense plot-wise.
Now, it is possible that Kubo couldn’t really come up with a plausible Bankai that would make sense in Aizen’s case, that much is true, but that is something we cannot really confirm or deny. We don’t think this s the case, though, as Kubo is known for coming up with solutions to his problems, regardless of whether he’s trolling us with them or not. So, we think that the reason why we haven’t seen Aizen’s Bankai is that it would not have made sense plot-wise and would not be lore friendly at that point; still, if the manga actually does continue, Aizen’s Bankai could be introduced, or at least mentioned and described at some point.
What could Aizen’s Bankai be?
So, now that we have told you everything about the background surrounding Aizen’s Bankai, we can actually tell you what it could be. There are multiple theories online, but we won’t be relying on them for one specific reason. Namely, the recent revelation of the original Gotei 13 Captains, the ones Kubo introduced as silhouettes back in the original manga, sparked a lot of fan theories surrounding them, their background, and the Royal Guard. Most, if not all of them, have been proven wrong. Tite Kubo is a very specific author and it wouldn’t surprise us if he, personally, read the theories and then wrote something completely different just to troll fans (although it’s unlikely), so each guess is usually shot in the dark.
That is why we won’t be focusing on any theories surrounding Aizen’s Bankai. It just wouldn’t make sense. What we are going to do is explain, based on what we know about the Bankai and the whole series, what we think Aizen’s Bankai could look like. Our theory is going to be based on the evidence we have from the franchise and knowing Kubo, really, our guess is as good as any.
Now, before we explain everything, here are the facts we have to consider. First of all, in most cases, the Bankai is an amplification of the Shikai’s basic powers. There are numerous examples of that, such as Shinji Hirako’s Bankai, Byakuya Kuchiki’s Bankai, Sajin Komamura’s Bankai, Toshiro Hitsugaya’s Bankai, Mayuri Kurotsuchi’s Bankai, and others.
Some are similar to the original Shikai, but slightly different, such as Soi Fon’s Bankai or Rōjūrō Ōtoribashi’s Bankai, whereas only a few are completely different, such as Kenpachi’s Bankai or Retsu Unohana’s Bankai. This means that the Bankai usually focuses on the basic powers of the Shikai and amplifies their power, speed, and other components (plus, they’re visually cooler).
The second fact we have to consider is the nature of Aizen’s Shikai. Namely, Aizen’s Zanpakutō is an illusion-based Zanpakutō and alongside his, only two other illusion-based Zanpakutō are known. They are Shinji Hirako’s Sakanade and Rōjūrō Ōtoribashi’s Kinshara. Kinshara is a very specific Zanpakutō, whose illusions are different than the illusions created by Aizen’s Zanpakutō, whereas Shinji’s Sakanade is very similar to Aizen’s in the sense that its illusions wholly confuse the opponent. This is why Shinji was somewhat successful when fighting Aizen, as the illusions of his Sakanade managed to confuse the former Captain, and why we are going to use Shinji’s Bankai as a basis for our theory.
The third and final fact we have is one thing we actually know about Aizen’s Bankai save for the fact that Aizen knows it. This has not been revealed in the original manga, but rather in the Can’t Fear Your Own World light novel series written by Ryōgo Narita, but with input from Tite Kubo, who has not refuted anything from the light novel as not being canon. Namely, the series confirms one fact about Aizen’s Bankai, and that is that it can affect only those that have already been hypnotized by his Shikai.
So, now that we have all of these facts, we can use them to form a theory about Aizen’s Bankai. We think that Aizen’s Bankai would actually focus on reality bending. Kyōka Suigetsu created illusions, but it did not alter the complete reality of its opponents. Aizen mostly used it on himself as he could manipulate what those affected saw.
The Bankai would amplify that power to a larger scale in the sense that it would not only create mere illusions but alter the reality of those affected completely. This would allow Aizen to manipulate his victims however he wanted, as he would have influence over their realities.
Now, if we compare this to Shinji’s Bankai, as Saknade is similar to Aizen’s blade, it does make sense. Shinji’s Sakashima Yokoshima Happōfusagari elevates the Shikai’s ability to confuse the opponent’s sense of direction in a way that influences their moral code as well; in that aspect, Sakashima Yokoshima Happōfusagari makes friends become enemies, as it completely alters their sense of reality. Aizen’s Bankai could work in the same way, making the illusion created by the Shikai stronger and more dangerous.
This theory would also make sense if Kubo avoided Aizen’s Banka because it would be too overpowered. Namely, Aizen was known for creating powerful and effective illusions that were almost indiscernible from reality; even Unohana wasn’t able to break through them, and she is enormously powerful.
Imagine such power amplified on everything around you, with Aizen manipulating what was going on. It could make even the strongest spiritual beings lose their minds and commit suicide, or it would allow Aizen to kill them without them even knowing. Since we know that even Yhwach was susceptible to Aizen’s illusions, such a power would have made the fight with Yhwach too easy and would not make sense from a narrative standpoint, which is why Kubo probably didn’t introduce it to the series.
Sure, Aizen’s Bankai wouldn’t be completely overpowered as it obviously has some limitations. It is debatable whether it would work fully on characters such as Yamamoto or Ichibei, who are enormously strong and could potentially resist it. It is also known that its effectiveness is limited only to those who have already been exposed to its Shikai, which means that it cannot influence characters such as Ichigo or Kaname, with the latter being immune to it due to being blind.
Knowing that Aizen’s Shikai’s effect can be annulled by touching the blade of the Shikai, there is a relatively easy way to counter Aizen’s Bankai, but it’s difficult to do so. There would probably be some other thing that could effectively counter Aizen’s Bankai, but since we don’t know what the Bankai is, we cannot specify it.
And that would conclude our story on Aizen’s Bankai. We tried our best to compose a theory based on what we know from the original works, and our theory is based on our knowledge of the Bankai, similar Bankai, and how the lore works. Whether it’s true or close to the truth remains to be seen, but we hope that you had fun reading it at least.