there are these things called breathing styles. Breathing styles are swordsmanship styles that make use of a technique known as Total Concentration Breathing, All breathing styles currently caught within the demon slayer corps are derived from sun breathing. Sun breathing is the first breathing technique. Most of the styles mimic nature like flame, water, and wind, and it replicates the user’s techniques and abilities. The weapons the people who use breathing styles are long ranged, maybe due to the shockwaves or air pressure generated from their weapon swinging and striking, the weapons is a single katana. Breathing styles are constantly created to suit a demon slayer’s combat needs, this is a result of new weapons being used for demon hunting (i.e. serpents, flowers, and love styles. When using a breathing style the user automatically visualizes themselves manipulating the subject behind the breathing style. It may seem if they are using magic, but they are not, though those that are less proficient in their style will visualize less than one who is. There is an advanced and esoteric breathing technique where the user inhales a maximum amount of oxygen within a specific pattern of breathing to raise their physical and mental powers to their limits. The effect includes a large amount of enchanted physical and mental abilities like superhuman characteristics like strength, speed, stamina, durability, and agility. It maximizes concentration and hyper information processing. At the most advanced level you are capable of clotting wounds from intense injury and slowing down the circulation of poison in the blood stream i.e. slow the process of poison spreading through your body and killing you. One last thing is Total Concentration: Constant this is a breathing state during the morning, noon, and night, and even while you are sleeping. Advanced demon slayers like Hashira can constantly maintain it. Learning to maintain a constant star requires alot of effort, the skill itself is elementary despite it requiring alot of effort. The Training process ivolves blowing into special types of super durable gourd. The objective is to blow into the gourd with enough strength to breakt it apart. The gourd is replace by larger and bigger variations of the same type of gourd. The largest known gourd is the size of a chair.