Demon Slayer is a massively popular fantasy shonen action series starring the compassionate demon slayer Tanjiro Kamado, who is on a quest to restore his sister Nezuko's humanity, no matter what. Along the way, Tanjiro met many new friends and allies, and the most powerful ally he has met thus far is Kyojuro Rengoku, the flame Hashira.
Kyojuro Rengoku is one of the most flamboyant and energetic of the nine Hashira, regardless of whether he's the strongest among them, and he was the star of the Mugen Train story arc. Kyojuro has a strong personality to match his intense flame-based breathing technique, and he sets an excellent example for Tanjiro not only as a demon slayer, but as a human being. His MBTI personality type reflects this, too.
Kyojuro Rengoku's MBTI Personality Type: ESFJ-A, The Consul
The Consul personality type, according to the metrics of the MBTI test, can be described as a lawful, socially adept protector and hero. These Consuls are slightly different from the Protagonist personality type, since Protagonists are more impulsive and spontaneous, while Consuls such as Kyojuro are more disciplined and law-abiding in their actions. They are more like soldiers or knights, and they keep rules and tradition in mind, while Protagonists can be more like a bull in a china shop at times.
Kyojuro's personality code, ESFJ-A, stands for Extraverted Observant Feeling Judging Assertive, making for an energetic personality that still has some restraint and purpose in its actions. Such people tend to be highly sociable and caring of others, and might even be the life of the party. At the very least, Consuls such as Kyojuro Rengoku are concerned about the well-being of others, even if they don't seek a massive circle of friends, and they act almost entirely on the behalf of those around them. Consuls also tend to be role models with their disciplined, affectionate and optimistic personalities, and can inspire anyone and everyone around them.
Kyojuro Rengoku's MBTI Personality Type In Demon Slayer
Nearly every single one of Kyojuro's scenes in Demon Slayer showcases his ESFJ-A personality type, including flashbacks involving him, his father Shinjuro and his younger brother Senjuro. In his younger days, Kyojuro was an enthusiastic and highly disciplined trainee demon slayer, spending hours each day practicing his technique to slowly but surely master the sword and become a Hashira like his father before him. That already establishes him as a Consul, and it helps that he had a deep emotional connection to his brother, inspiring him to also do his best and realize his potential. Only a true Consul like Kyojuro could set such a good example with his tireless discipline and passionate personality.
In the present day, during the main events of Demon Slayer, Kyojuro is to Tanjiro's team what he once was to his brother, and acts like a protective big brother to them during the Mugen Train story arc. As a true Consul, Kyojuro will unquestioningly follow orders from his superior officers and risk his life for his duty, and he even objects to other characters shielding the demon Nezuko from other slayers. To a Consul like Kyojuro, laws and tradition are important and shouldn't be broken too casually. However, eventually, Kyojuro accepts Nezuko and raises no further objections to her presence.
During the Mugen Train story arc, Kyojuro expresses his ESFJ-A personality once again, enthusiastically fulfilling his duty against powerful demons and empowering Tanjiro, Inosuke and Zenitsu with his good example. He risks his life to defend them, and when he is dying after his battle with the demon Akaza, Rengoku makes sure that his parting words are inspirational and motivating, imparting one last Consul-style gift to his valued friends and allies.
Moreover, as a true Consul, Kyojuro stubbornly refuses to break demon slayer law and accept Akaza's offer to become a demon himself, even if it would give him strength and save his life. If a Consul can't do something right, they won't do it at all, and that kind of discipline and sense of duty is exactly what Tanjiro himself will need as he proceeds to the upcoming Entertainment District story arc.