Breath Styles are swordsmanship styles practiced and taught by the Demon Slayer Corps. They are capable of making their users fight on par with Demons, and are generally used with Nichirin Blades to slay demons, with a few exceptions.
Overview
All Breath Styles currently taught within the Demon Slayer Corps derive from the the Breath of the Sun, the first one ever created.
Breath Styles make use of specific and concentrated breath patterns, which increase the user's lung capacity and amount of oxygen in the blood.
The increased amount of oxygen allows the user to increase their physical abilities and mental concentration to the point where they can match a Demon's strength. Focused breaths are also capable of clotting wounds from severe injuries and slowing down the circulation of poison in the bloodstream.
Full Focus Breathing
Also known as Total Concentration in some translations, this is a state where Breath Style users inhale the maximum amount of oxygen within a specific breath pattern to raise their physical and mental strength to their utmost limits. It is often used by Demon Slayers to temporarily prepare a decisive attack.
Advanced Demon Slayers, such as Pillars, can constantly maintain a Full Focus Breath state, even while asleep. There is an immense difference in strength between someone who can maintain Full Focus Breathing at all times and someone who cannot.
Known Breath Styles and Users
Branches
Chain Order of Breath Styles
Kyojuro explaining the chain derivatives of the Breaths