Breathing styles are the main power system within Demon Slayer, and have been cultivated over hundreds of years. There exist some characters though, with unique enough fighting styles that they were able to invent brand new breathing styles.In the harsh world of Demon Slayer, the gap in strength between demons and humans is only made manageable due to the use of breathing styles. By precisely controlling their breath and movements, demon slayers are able to enhance traditional swordsmanship and reach a level of power that can contend with the supernatural demons. Most characters use long-established and reliable breathing styles, but for some, the old styles were not appropriate for them, so they had to develop their own forms of swordsmanship.
Inosuke Hashibira
Having been raised in the forest by wild boars, Inosuke never learnt how to even read, let alone wield a sword. What he did learn though, was how to fight like a wild animal. So, when he ended up defeating a demon slayer who was passing through his forest, Inosuke took interest in the art of swordsmanship, but bent it to his own animalistic preferences.
Thus, beast breathing was born. Inosuke not only customized his nichirin blades by denting them to be more saw-like, he also chose to wield 2 swords as opposed to the usual 1. These modifications are meant to imitate the fangs of a wild animal, ripping and tearing with reckless abandon. The style also makes great use of Inosuke’s agility and strong senses, with several forms involving aerial attacks, and one entirely dedicated to locating enemies.
Shinobu Kocho
While she was originally trained in the flower breathing style, Shinobu eventually found that she couldn’t cut the heads off demons due to her small stature. Usually this weakness would spell the end of a demon slaying career, but Shinobu had another chance due to her affinity for making poison. So, through her personal chemistry skills and determination, she not only invented the insect breathing style, but also managed to become a Hashira.
The center of insect breathing is the aforementioned poison, making it one of the most preparation-intensive styles. Shinobu keeps a mixture of poison in her scabbard at all times, and adjusts the potency depending on the demon she’s facing. To best deliver this poison, she also adapted her nichirin sword to be more pointed and thin, almost like a rapier. This is to assist in insect breathing’s focus on stabbing opponents in order to inject poison into them. Coupled with Shiinobu’s natural speed, this style aims to float like a butterfly and sting like a bee.
Tengen Uzui
While Tengen had as much combat training as any demon slayer could ask for, his training was actually in espionage, not direct combat. As just one sibling in a family of ninjas, he had to endure many years of harsh training by his father, which led to the deaths of most of his siblings. It’s unclear what Tengen did immediately after leaving the ninja life with his wives, but he was soon recruited by Kagaya Ubayashiki, the current leader of the demon slayers. With such a severe change in career, Tengen had to adapt his previous training and personality into a breathing style all his own.
As a ninja, Tengen no doubt had an affinity for sound. Unexpectedly though, he chose to be flashy over sneaky. His sound breathing makes use of giant, cleaver like swords connected by a chain, making it a dual wielding style. On top of that, its forms also make use of small bombs that only a ninja like Tengen would be fast enough to throw mid-fight. By combining the small explosions and large swords, sound breathing is not only a style focused on wide-range attacks, but also being as flashy as humanly possible.
Mitsuri Kanroji
Mitsuri’s backstory is one of the least traumatic of any demon slayer, but it still had a large effect on her self-esteem. Primarily, her unique muscle composition meant that she was viewed as being too physically strong for a woman, and thus was ostracized by men. Eventually, she joined the demon slayer corps, and found an environment that accepted her strength. While she originally learnt flame breathing under Kyojuro Rengoku, her raw strength was incompatible with the style, leading her to the development of her own style.
The resulting love breathing style took many queues from flame breathing, but also went in a wildly different direction. The style makes use of Mitsuri’s strength and agility with a lot of multi hit forms and oppressive attacks. These are made even more dangerous by Mitsuri’s unique nichirin blade, which also functions as a whip. This blade makes it so that Mitsuri can not only strike foes from a decent range, but also allows her to hit a foe multiple times instantaneously.
Obanai Iguro
While anime fans might know Obanai as only a snide, disrespectful character, his full personality and backstory make his antisocial behavior more understandable. Particularly in that he was raised within a cult that worshiped a snake demon, and only valued him for his unusual and easily mocked appearance. A further hindrance to his life was his partial blindness, something he compensates for with the aid of his pet snake. Due to this sordid past and his small stature, Obanai opted to develop his own style of breathing.
Like the name implies, serpent breathing is a style that mimics the winding, twisting motions of a slithering snake, similar to real life snake-based martial arts. It makes use of Obanai’s stature by emphasizing slipping through thin gaps in an opponent’s assault, and responding with swift strikes. His curved sword is reminiscent of a real life Kris sword, and allows him to bend his attacks in unusual ways to make serpent breathing possible.