Kamado Tanjiro, the protagonist of the Demon Slayer anime series, is a young boy whose family was killed by demons and whose sister was turned into a demon. Tanjiro enters the deadly world of demon slayers because he is determined to rid the world of demons and return his sister to human form.
In the Demon Slayer anime series, fans meet a wide variety of fascinating characters, from expert and powerful demon slayers to fearsome demons themselves. There are, however, a few among them who are light years ahead of the rest in terms of brains and cunning. Few people, whether skilled tacticians, analysts, or clever inventors, have proven their worth in the hidden fight between demons and humans via quick wit and strategic thinking.
8 Tanjiro Kamado
Tanjiro Kamado, the protagonist of the anime series Demon Slayer, is shown as a character who develops in both strength and intelligence as the story progresses. Tanjiro is frequently observed throughout his fights, assessing his own skills and those of his opponent to choose the most effective method of decapitation.
Tanjiro is also admired for his speed and certainty in making choices. Giyu Tomioka remarked on Tanjiro's quick thinking because it helped him stop Giyu's assault on Nezuko when they first met. Tanjiro, unlike many other demon slayers, is able to keep his cool under pressure and make the most logical decisions for completing his mission.
7 Yoriichi Tsugikuni
As the creator of the Sun-breathing style, which all other breathing styles descended from, Yoriichi Tsugikuni’s battle intellect is unparalleled in the Demon Slayer anime series. As a child prodigy, Yoriichi was incredibly skilled with a sword and single-handedly developed many ways for demon slayers to successfully battle demons.
Yoriichi’s Sun-breathing style was developed based on the various vital organs Muzan possessed. The 13th form of the Sun breathing style was tailor-made to instantly destroy Muzan’s vital organs, which constantly move around in his body. The intellect, skill, and observation required to tailor a breathing style to end the King of Demons is nothing short of incredible.
6 Shinobu Kocho
Shinobu's fighting strategy as the insect Hashira relies less on brute strength and more on her wit and adaptability. Being the physically weakest of the several Hashira, Shinobu began using poison to eliminate demons.
To be effective when employing poison against demons, one must have extensive knowledge of plants, chemicals, and demon physiology. It's no easy task to sneak up on demons and poison them where it will cause the most damage while also engaging them in combat, but Shinobu pulls it off with ease. Although she creates diverse potions that treat otherwise fatal injuries, her knowledge of plants and medical herbs is by no means insignificant.
5 Giyu Tomioka
As Water Hashira, Giyu helps the Demon Slayer Corps in ways that are very important. Because of his famously uncommunicative demeanor, many of the other characters and even some of the fans have no idea what he's thinking. Giyu's stoicism, which lets him analyze information calmly and rarely get angry, is a big part of why, despite being unpredictable, he is so good at analysis and tactics.
When confronted with danger, Giyu takes the most prudent and sensible course of action possible. Since Tanjiro's sister, Nezuko, is a demon, Giyu considered the likelihood of her consuming humans before deciding to kill her out of pure hatred. Many of the lower-ranking members of the Demon Slayer Corps look up to him for his strategic thinking and analytical talents as the cool and powerful Hashira that he is.
4 Gyomei Himejima
As the Stone Hashira is portrayed in the Demon Slayer anime series, Gyomei Himejima is incredibly powerful and sentimental. With a deep connection to living things, Gyomei easily cries over the most insignificant things. Despite his tendencies, Gyomei is incredibly analytical, in and out of battle.
Gyomei has proven himself in many situations, as he is trusted by Kagaya Ubuyashiki to lead and give instructions to the other Hashiras. With a high level of analytical and emotional intelligence, Gyomei ranks above most characters in the Demon Slayer series in terms of intelligence. Gyomei’s ability to quickly identify the strengths and weaknesses of demons moments after analyzing them makes him an invaluable asset to the demon slayer corps.
3 Tamayo
Tamayo is the only character in the Demon Slayer anime series who can compete with Muzan Kibutsuji, the show's scientific prodigy. Her work on the Anti-Kibutsuji Drug, which severely weakens Muzan and stops him from splitting into several parts and escaping on the edge of death like he did when he fought against Yoriichi Tsukiguni, was a major factor in bringing an end to Muzan and other demons.
Tamayo makes the Anti-Demon Blood Coagulant and the Anti-Kibutsuji Medication. The Anti-Demon Blood Coagulant stops demons from using Blood Demon Arts, making them less useful in fighting the different powerful Hashiras.
2 Kagaya Ubuyashiki
Kagaya Ubuyashiki, head of the Demon Slayer Corps, is a brilliant tactician and an upstanding human being. One of Ubuyashiki's most distinguishing qualities is his openness to innovative strategies for defeating demons that can offer humanity an advantage.
The capacity of Ubuyashiki to see past the obvious to the true motivations behind things is another quality that sets him apart. Ubuyashiki has a profound insight into human nature and plots out clever concepts for combat against demons thanks to his analytical, creative, and strategic thinking. Ubuyashiki's analytic precision is further enhanced by the fact that he possesses a rare power that enables him to foresee the results of events that have not yet occurred.
1 Muzan Kibutsuji
The Demon King Muzan Kibutsuji has seven hearts and five brains, making him one of the most intelligent characters in the Demon Slayer anime series. Muzan is an extremely bright man who has spent ages perfecting his art and is an expert in chemistry and medicine.
Muzan's manipulation abilities are even more amazing than his knowledge of chemical and biological engineering procedures. He manipulates the minds of his demon minions to do his bidding by instilling a sense of dread and promising vengeance. Muzan is also very interested in various forms of higher learning as he strives to achieve perfection in everything he does.