Throughout the entirety of the series, there have been several Jujutsu Kaisen characters who have been seen using a powerful technique called Domain Expansion, which acts as a complete game-changer during intense battles. That said, only a select few can make use of Domains, and whoever does, are some of the strongest characters of the series.
Similar to Domain Expansions, Tite Kubo's Bleach series has the famous Bankai, a powerful technique that can only be used by some of the strongest characters. Given the striking similarities between Bankai and Domain Expansion, fans have often held discussions about which Jujutsu Kaisen characters would be able to achieve a Bankai.
While the names of Satoru Gojo and Ryomen Sukuna certainly come to mind as characters who can achieve a Bankai, let us look at those Jujutsu Kaisen characters who would unfortunately never be able to do so.
Nobara Kugisaki and 9 other Jujutsu Kaisen characters who could never achieve a Bankai
1) Panda
Apart from being a second-year student at Tokyo Jujutsu High, Panda is also one of the most beloved Jujutsu Kaisen characters due to his kind-heartedness and benevolent nature. However, Panda is also one of the many Jujutsu sorcerers who could not achieve Domain Expansion. As such, it'd be difficult to think of him acquiring the Bankai anytime soon.
While Panda is a capable sorcerer in his own right, he is certainly nowhere near being one of the strongest characters. Therefore, it is safe to assume that Panda will likely never rise to the level of Domain Expansion or Bankai users.
2) Nobara Kugisaki
Nobara Kugisaki was a promising first-year student at Tokyo Jujutsu High who had the potential to be a great Jujutsu sorcerer one day. Unfortunately, she never got to reach her full potential, as she was seemingly killed off during the Shibuya arc.
Although a lot of her fans are still hopeful of her return to the story one day, it probably has a higher chance of happening than her getting a Domain Expansion. Therefore, Nobara will likely never reach the level of achieving a Bankai either, given the similarities between the two powerful techniques.
3) Mai Zen'in
Despite possessing the powerful ability to create anything from nothingness, Mai Zen'in was restricted by her extremely low level of Cursed Energy. In fact, she is a Grade 3 sorcerer with very little affinity for Jujutsu sorcery. As such, she joins the list of the many Jujutsu Kaisen characters who could never be able to achieve a power as great as a Bankai.
4) Kasumi Miwa
Kasumi Miwa, a second-year student at Kyoto Jujutsu High, was one of the most likeable Jujutsu Kaisen characters despite her limited screen time. That said, she possesses little affinity for Jujutsu sorcery, as she does not even possess an innate Cursed Technique.
Although she was capable of using her sword and the New Shadow Style techniques pretty efficiently, she often used to get overpowered by her opponents. Furthermore, she is no longer even capable of using a katana again due to a binding vow she made during the Shibuya arc. As such, it is evident that Miwa cannot hope to rise to the top of the Jujutsu world anymore, much less aim to acquire the power of Bankai.
5) Momo Nishimiya
A third-year student at Kyoto Jujutsu High, Momo Nishimiya's official ranking as a sorcerer is somewhere around semi-grade 2. Since her Cursed Technique usually allows her to stay afloat on a broom, Momo usually stays above the battlefield and acts as a scout for her allies.
Her lack of any significant combat abilities certainly doesn't work in her favor in most situations, as seen during her confrontation with Kenjaku and Uraume in the Shibuya arc. Given her current capabilities, one certainly cannot expect Momo to rise to the level where she can acquire the power of the Bankai.
6) Takuma Ino
Takuma Ino is a Grade 2 Jujutsu sorcerer who is capable enough to rise to semi-grade 1 if he chooses to. He has a decent amount of Cursed Energy and hand-to-hand combat skills, along with a fairly useful Cursed Technique.
While he is a capable sorcerer in his own right, Ino certainly isn't on the level where he could hope to gain a Domain Expansion, much less a Bankai.
7) Kento Nanami
Kento Nanami is one of the most capable fighters in Jujutsu Kaisen. He is the model example of what a Grade 1 sorcerer should be and possesses the power to back up the claim as well. He was strong enough to fight on par with Special Grade Cursed Spirits like Mahito, who deemed the former to be a worthy opponent.
That said, it can be argued that Nanami couldn't reach his full potential as he stepped away from the life of Jujutsu sorcery for quite some time. In fact, when he was trapped inside Mahito's Domain Expansion, Nanami didn't have much of a choice other than accepting his death. As such, it is evident that, in spite of his power and efficiency as a Jujutsu sorcerer, Nanami would likely not meet the criteria for acquiring the power of Bankai.
8) Aoi Todo
Aoi Todo had an exceptional talent for Jujutsu sorcery, as he attained the rank of a Grade 1 sorcerer as a student. He became one of Jujutsu High's strongest sorcerers after training under Yuki Tsukumo.
As seen in the series, Todo was capable enough to fight on par against someone like Mahito and was even able to avoid certain death when the latter unleashed his Domain Expansion on him. That said, Todo is also likely to not be at the required power level to acquire the Bankai. Additionally, his battle against Mahito seemingly ended his life as a Jujutsu sorcerer for good, as his Cursed Technique was rendered useless due to the loss of his hand.
9) Toge Inumaki
Toge Inumaki is a highly skilled and capable Jujutsu sorcerer who has attained the level of semi-grade 1 in his second year at Tokyo Jujutsu High. He is a skilled combatant who was capable enough to take on solo missions on his own during his first year. He also possesses a powerful inherited Cursed Technique called the Cursed Speech.
As powerful as Inumaki's Cursed Speech technique was, it had an adverse effect on his own health. Prolonged use of the Cursed Speech often took a huge toll on Inumaki, as he was frequently seen to be coughing blood after using it. While Inumaki certainly has the potential to rise to greater heights in the Jujutsu world one day, he certainly cannot hope to reach the level where he could acquire a power like the Bankai.
10) Utahime Iori
Utahime Iori serves as a teacher at Kyoto Jujutsu High. As a semi-grade 1 sorcerer, she does not possess any combat skills and mostly acts as support for her allies. Given that her Cursed Technique only allows her to amplify her and any other willing participant's Cursed Energy to 120 percent, it's hard to imagine her being powerful enough by herself to wield the power of the Bankai.
Final Thoughts
While a lot of the aforementioned Jujutsu Kaisen characters are capable sorcerers, it should be noted that they are pretty unlikely to be on a level where they can hope to achieve a power as great as a Bankai or a Domain Expansion.
Among the entire cast of Gege Akutami's magnum opus, only a select few Jujutsu Kaisen characters like Satoru Gojo, Yuki Tsukumo, Yuta Okkotsu, Ryomen Sukuna, and Mahito may be able to achieve a Bankai.
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