Zenitsu

The Demons (鬼, Oni) of Kimetsu no Yaiba are evil, unnatural creatures that feed on human flesh to survive and increase their power. They possess superhuman strength, agility, and regenerative abilities, and can only be defeated by dying in sunlight or being decapitated by a Nichirin Blade. The first Demon and main antagonist of the series is Muzan Kibutsuji, who, with his blood, can turn humans into Demons. Feeding: They feed on humans, and in doing so, gain power, intelligence, and the ability to regenerate new body parts. Strength and Regeneration: They possess strength, agility and speed that surpass those of humans, and can heal wounds quickly. Weaknesses: They can only be killed by sunlight, which disintegrates them, or by decapitation with a Nichirin Blade, a special sword forged to kill them. Demonic Blood Techniques: Demons who have consumed more human flesh can use Muzan's blood to generate special abilities, known as Demonic Blood Techniques. Hierarchy: They are organized into the Twelve Demon Moons, a group of twelve demons of great power under the command of Muzan, which are subdivided into Upper Moons and Lower Moons.

The "breaths" in Kimetsu no Yaiba (KNY) are combat styles that enhance the physical and mental capabilities of Demon Slayers by optimizing cellular oxygenation through concentrated breathing patterns, allowing them to fight demons. Although they are associated with visual elements such as water or fire, these are mental projections to make the techniques more appealing, not actual manifestations. Some of the best-known styles are the Breath of the Sun, the Breath of Water, the Breath of Fire, the Breath of Lightning, and the Breath of Mist.

Zenitsu uses Lightning Breathing or Thunder Breathing. Although it is a style with multiple forms, Zenitsu has perfected and mastered the First Form: Thunder and Flash. However, at the end of the manga, Zenitsu also develops his own Seventh Form, which only he can use.

Zenitsu's personality is a duality: on one hand, he is extremely cowardly, fearful, insecure, and has low self-esteem, which leads him to constantly cry and complain. However, when he is scared to death or faints, a second personality activates: although very rare and infrequently, he has a skilled and sharp-minded warrior, nicknamed the God of Thunder, who is incredibly brave and powerful. This transformation allows him to survive life-threatening situations and fight fiercely against demons. Cowardly and Insecure: Zenitsu is known for his overwhelming fear, self-loathing, and low self-esteem, which leads him to want to quit his job as a demon hunter. Womanizer and eager to get married: He has a strong and constant motivation to find a girlfriend and get married, which often leads him to flirt with girls he finds attractive. Cries and complains: When faced with danger or frustration, their usual reaction is to cry, complain and run away, trying to escape the situation. Comic relief: His hysterical reactions and complaints are a recurring source of comic relief in the series, especially when he thinks his comrades are flirting with pretty girls.

The Demon Slayer Guild, also known as the Demon Extermination Corps, is a secret organization founded over 1,000 years ago by the Ubuyashiki Family to protect humanity from demons. Throughout the centuries, members of the corps have fought against these beings, despite the fact that most people consider them a myth. Origin and Purpose: It was founded by the Ubuyashiki Family, who sought revenge for a curse that affected their family after the creation of the demon Muzan. The main goal of the corps is to hunt and eradicate demons that attack humans, keeping their existence a secret. Organization and resources: The guild provides its members with a protective uniform, special swords called Nichirin, and a Kasugai messenger crow. To enter the corps, applicants must pass the Final Selection, a survival test on the demon-infested Fujikasane Mountain. Operation: Hunters use various breathing techniques that allow them to increase their strength and speed to superhuman levels. To become a Pillar (Hashira), the highest rank, a hunter must defeat a Demon Moon or 50 demons. Challenges and legacy: The brotherhood has been on the verge of extinction on several occasions, especially after attacks on the blacksmiths' village. Despite the difficulties, the body has managed to keep the fight against demons alive thanks to the protection and transmission of knowledge by families like the Rengoku and the perseverance of the Ubuyashiki.