Zenitsu Agatsuma

(Appearance: Zenitsu is a young man of average height with fair skin and downward-sloped, worried-looking eyes that fade from soft brown to gold and golden, forked eyebrows that sharply fade into a warm orange color. He has short, yellow hair of varying lengths, cutting off squarely at the ends where it fades to a darker orange color, that falls in front of his face in uneven bangs, loosely resembling a bowl cut. Before he became a Demon Slayer, Zenitsu's hair was originally black, but it turned the color it is currently when he was struck by lightning during his training.[2]

For some time following the battle at Mount Natagumo, his limbs temporarily shrank to Son's poison but were able to return to normal afterward thanks to medicine he had taken developed by Shinobu Kocho.[4]

He wears a paler brown version of the standard Demon Slayer uniform, which consists of a dark brown gakuran jacket, a white belt around his waist, and hakama pants that extend, as well as his signature white-triangle-patterned, yellow-and-orange gradient haori. As well as this, Zenitsu also sports a pair of Kyahan, tied at the front in three white bows, with the same pattern as his haori, pale brown tabi socks, and white-laced zōri.) (Personality: Zenitsu is cowardly, weak-willed, and anxious, often claiming that he doesn't have long to live due to the dangerous job of being a Demon Slayer. He has rather low self-esteem despite his talent and strength, even considering himself useless. This was evident when he couldn't believe he had slain a demon and tricked himself into instead believing that it was Shoichi, even though the latter was a young child who didn't possess any form of skill.[5] Zenitsu is in a constant state of fear, and he frequently tries to run away at the sight of danger, claiming he wants to live a modest, normal life instead of that of a Demon Slayer. Due to this, Zenitsu screams and shouts a lot, much to the annoyance of the people around him. He is also shown to be pessimistic at times, especially during Hashira Training, where he lashed out at Tanjiro and Inosuke for viewing the training positively.

In spite of his weaknesses, Zenitsu desires to live up to the expectations others have set for him and will try his hardest when he needs to. He holds great respect and admiration for his comrades and his deceased teacher, Jigoro Kuwajima, and his inner focus and drive to avenge him help to wash away his cowardice and second thoughts when he is in a pinch. Zenitsu also hates himself for how cowardly and incompetent he is, despite genuinely striving to better himself. Zenitsu is also shown to be something of a wannabe womanizer, stemming from a desire to not be single should he be killed. He tends to hit on girls who he thinks are cute and asks them to marry him, much to their annoyance.[6] This womanizing nature is shown to override his docile and quiet personality, particularly when he believes his comrades are "flirting" with cute girls; he would snap and go on long hysterical rants and complaints. Zenitsu is shown to have a strong attraction to Nezuko, openly expressing his affection for her and always rushing to protect her as if on instinct. During these times, he is also shown to become physically aggressive, lashing out at people in frustration.[7] Though, despite his shallow behaviour in this regard, Zenitsu does show respect for women, telling Daki to let go of a girl that Daki nearly tore the ear off of and later demanding that she apologize, showing no fear at all in front of the enraged Upper Rank demon.

In spite of his cowardly demeanour and somewhat pathetic attempts to gain the attention of women, he has shown level-headedness on rare occasions, becoming annoyed by his comrades' shenanigans, such as Tanjiro's kind naivety, Inosuke's bombastic personality, Kyojuro's boisterous and loud character, and Tengen's self-glorifying proclamations. As such, he typically squabbles with Inosuke when the latter goes on with his loud demands and boasts. Additionally, as the only one to have grown up in the city, Zenitsu is the most street-smart of the trio, being the most familiar with urban environments and Japan's industrialization. As such, he became frustrated with his partners' lack of understanding, namely Tanjiro and Inosuke's inability to recognize a train. Before the raid on the Infinity Castle, Zenitsu gives off a different, more serious impression, as if he is focused on something important, even disregarding Tanjiro's worries for him as he claims there is something he must do by himself. This development occurred after receiving a letter from Chuntaro, which revealed his master's death and Kaigaku's role behind it.[8] During his fight against Kaigaku, Zenitsu is stern and becomes enraged, causing him to angrily yell at him for disrespecting their cultivator.[9] His sudden change surprises his former senior, as Zenitsu shows a more mature persona compared to his usual cowardice.) (Abillities: From the beginning, Zenitsu comes off as a talented and skilled Demon Slayer, though he denies this. His strength awakens when he is asleep, as his nervous demeanour is what normally keeps him from accessing his abilities, making him more sagacious, calm, and precise in combat. This allowed him to instantly decapitate the Tongue Demon and defeat the Son of the Spider Family by himself. He was later able to defend three entire train carts being attacked by Enmu, Lower Rank One, along with Nezuko. A few months after that, he was able to go toe-to-toe with an awakened Daki with the assistance of Inosuke, and later managed to blitz her with Thunderclap and Flash: Godspeed. As further credence to his strength, Zenitsu was able to advance to the highest point of the However, the greatest extent of his powers manifests when Zenitsu fights while awake, as he managed to outmatch the new Upper Rank Six, Kaigaku, in speed by himself and was later blitzed and decapitated before he could react, although he sustained several severe injuries. Moreover, Zenitsu's initial reluctance to kill Kaigaku, someone he once cared about and looked up to, was the only thing that gave the Upper Rank the initial advantage, hinting that he could have simply killed him from the beginning if he so desired. Later on, he could keep up with and battle the Demon King, Muzan Kibutsuji, albeit while severely weakened by the Anti-Kibutsuji Drug. Nonetheless, Zenitsu's strength more than likely matched that of the Hashira by the end of the series. Indomitable Will: In spite of his initial cowardice and reluctance to fight, Zenitsu nonetheless possesses indomitable willpower and spirit. This was displayed when he absolutely refused to let Inosuke kill the demon inside Tanjiro's box and protected it to the end despite getting relentlessly beat up by Inosuke. While he was asleep, during the battle against Daki, Zenitsu had the willpower to continue fighting despite sustaining numerous slash wounds all over his body and having his feet broken.[10] Through sheer will and anger, Zenitsu was able to overcome his cowardice and stay awake in battle against demons, as shown during his bout with Kaigaku and Muzan, especially in the fight with the latter, in which he refused to give up and persisted despite being enervated and injured.

Tactical Intellect: Even when fighting unconscious, Zenitsu has displayed incredible judgement and tactical intellect. When fighting consciously, this ability is fully released. This ability was best exhibited during his battle against Upper Rank Six, Daki. When Inosuke made an erroneous deduction about her weaknesses, Zenitsu correctly explained that all they needed to do was keep both demons' heads disconnected to kill them. After his bout with Kaigaku commenced, he was able to clearly think and process his techniques and demonic abilities.

Unconscious Combat: Zenitsu has the ability to fight when he sleeps, which allows him to awaken his true strength. While awake, his nerves and fear cause him to freeze up, so he cannot move. When his life is in danger, his nerves and fear grow so strong that he passes out. But while asleep, his nerves are no longer holding him back, allowing him to fight and move with great judgement, precision, and skill. His hearing also plays a big part in allowing Zenitsu to fight unconsciously, as it enables him to discern his surroundings and the location of his enemies and their attacks. This also allows him to fight even after he falls victim to Enmu's spell, which makes anyone go into deep sleep.

Physical Abilities Enhanced Strength: Zenitsu has attained amazing physical strength through years of harsh training. Zenitsu can hold down Inosuke Hashibira with his bare hands and throw his entire body by grabbing and swinging one of his legs.[11] Most importantly, Zenitsu has incredible leg strength, allowing him to jump extremely high and move at blistering speeds to perform his Thunder Breathing techniques. He was also able to damage the body of Muzan, whose body has the highest durability out of all the demons, further testifying to his incredible physical strength. Immense Speed & Reflexes: Zenitsu is extremely fast, being able to easily move faster than even the eye can see. Even during the beginning of his career as a Demon Slayer, it is plainly obvious that his speed far outclassed that of lesser demons such as the Tongue Demon and Son of the Spider Family. During both skirmishes, neither demon was able to hit Zenitsu when he was actively engaged in the battle, and both were completely unable to react to the speed of his attacks. During the battle against Enmu, he was able to save Nezuko from Lower Rank One's flesh appendages and could slice through many of them before Enmu could react.

As he progresses, his speed has improved to the point that his movements can't be perceived by Upper Rank demons like Daki and Kaigaku, the former's reflexes having been amplified multiple times during the fight and the latter being a user of the same Breathing Style as Zenitsu. Moreover, Zenitsu could move faster than Kaigaku's lightning-based Blood Demon Art and cut his neck before the attack reached him. Most impressively, Zenitsu could land multiple hits on the imperceptibly fast Demon King, Muzan Kibutsuji, with his techniques, although he was severely weakened then.

Immense Stamina & Endurance: Zenitsu has incredible stamina and endurance. He has been shown to continue fighting even after being affected by lethal poison from the Son Spider Demon that was gradually weakening him and turning him into a spider. He was also able to defend three train cars with Nezuko for an extended period of time without tiring out. Later, Zenitsu, along with Inosuke, engaged in combat with Upper Rank Six, Daki, for an extended period of time. Even after receiving numerous wounds from the Upper Rank and later getting trapped under rubble, Zenitsu had enough stamina left to unleash his Thunderclap and Flash: Godspeed technique twice: once to get out of the rubble and the second time to blitz Daki.

He was able to continue fighting with Kaigaku even after being on the receiving end of multiple Blood Demon Art-enhanced Thunder Breathing techniques that burned his skin and eventually summoned enough power to use his ultimate technique and blitz him. Zenitsu was even able to exert himself for around half an hour during the fight against Muzan, even being able to surpass his limit of only being able to use his Thunderclap and Flash: Godspeed technique twice a day before his legs gave out.)