Summary
The Selfless State - otherwise known as the Realm of the Highest/ Domain of Supremacy is portrayed as the ultimate pinnacle of physical combat in theDemon Slayerseries, not many Demon Slayers are able to enter this state, and it is known to be a mysterious and highly esteemed state of being.
The selfless state is widely known as the profound state of being eradicated of the one’s fighting spirit. This means that when in this state, a person is able to hide their feelings of anger, hatred, bloodlust, and the determination to fight which are common to human nature when in a battle.

Enter The Selfless State
What makes the selfless state extraordinary is that it requires intenseamounts of discipline making itextremely difficult to attain. Not all humans are able to enter this state as it would take an enormous amount of willpower to do so. It is known that even the most calmed and composed individuals typically exhibit some degree of either the fighting spirit or anger because of emotions that are deep-rooted in humans from birth. From the Stone Age to the present day, humans have always been taught to fight to survive the dangers of the world, the complete absence of these emotions is a rare trait. The series also states that even infants emit a faint trace of the fighting spirit. Reaching this state also requires a deep understanding of one’s own emotions and high levels of self-control, where one would have to negate the negative emotions. Primal instincts arising even in the most dire situations can prevent one’s chance of entering this mysterious state.
The selfless state is not just known to humans but to demons as well,Akaza was a demon well versedin the techniques of martial arts for centuries, but was unable to find someone who had attained this state until he had battled with Tanjiro. One of Akaza’s traits as a demon was extrasensory perception, this means he could immediately gauge the fighting spirit of a person just by looking at them, this is seen during his battle with Kyōjurō Rengoku, where he could sense the immense fighting spirit he emitted. This was also seen when Muzan first encountered Yoriichi Tsugikuni, Yoriichi was also capable of activating the selfless state, which is why Muzan did not anticipate the possibility of being defeated, he could not detect the fighting spirit or hatred emitting from Yoriichi, andunderestimated Yoriichi’s power, almost resulting in his death.

Advantages in Battle
The uniqueness of the selfless state lies in its effectiveness in confusing opponents who have extremely sound extrasensory perception during combat. When in a selfless state, the fighting spirit immediately becomes hidden, making them invisible to opponents who depend on extrasensory perception, giving them an advantage on the battlefield. To further enhance the selfless state, it can be combined with Transparent World, a technique that allows a user to see things in transparent form. The Transparent worldtechnique gives the userthe ability to see into an opponents body to visualize their muscle and joint movements to predict their next attack as well as look for weak points. These two skills combined are the epitome of power in theDemon Slayerseries and are also highly sought-after techniques.
The only known users of the selfless state are Yoriichi Tsugikuni, Tanjuro Kamado (Tanjiro’s father) and Tanjiro Kamado. The selfless state is a testament to the limits a human can surpass through rigorous training, breath control, and a deep connection to their senses. The selfless state concept promotes the importance of discipline, perseverance and the pursuit to greatness with extraordinaryabilities which contributes toTanjiro’s growth throughout the series.