UAStop talking. I will win. That's... what heroes do.
Katsuki is a young man of average height, with ash blond, spiky hair and red eyes. At school, he wears the standard Yuuei uniform, save for the customary red tie. Underneath his blazer, he wears a white button up shirt, but keeps the first couple buttons unbuttoned. Despite wearing a belt along with the uniform's green pants, he does not pull them up all the way, giving his pants a baggy appearance.
His hero costume is composed of a fitted black sleeveless V-neck tank top with an orange X with the top half borders his shirt collar. His costume also has a seemingly metallic neck brace fashioned and used as a collar with three holes in both sides. His sleeves reach from within his large grenade-like gauntlets to his biceps. His belt, which also carries grenades, holds up his baggy pants with knee guards. He occasionally wears his hero mask that has large, flare-shaped cloth.
Katsuki is a very crude and aggressive person that has a tendency of bullying Izuku Midoriya, who he also treats in some ways as a rival.
Brutal and bloodthirsty, he smiles eerily when he's put into battle. While battling, his personality reflects his fighting style. His brutish way of fighting is shown through the Battle Trial: mercilessly assaulting Izuku and having no regard for nearby objects, merely destroying them with his power. Despite this, he's quite talented in fighting, able to use his Quirk to not only destroy but to maneuver around the battlefield.
While not the most mentally stable hero-in-training, nor having the image of one, he knows who his enemies and allies are. Cold to his allies, though not to the extent of friendly fire, but colder and brutal to his enemies. As the series progresses, his outbursts become less aggressive, usually becoming more comical, as he mostly gets angry at even small things like teasing. With that in mind, Katsuki seems to mature slowly but is still quite cold and distant.
He has a superiority complex and wants to be first and the best at everything. He doesn't like when people look down on him, as if they were superior to him; thus, it diminishes his already short fuse. Despite his extreme arrogance, he also thinks of people such as Izuku Midoriya as an obstacle on his path to becoming the greatest hero. Because of his complex, he's implied to be anti-social; He seems not to care for much people as he doesn't remember his classmates' Quirks or names despite being in Yuuei for some time. He does, however, remember the names of people who give him a challenge or whose ability he respects, such as Ochako Uraraka.
Ironically, his inspiration for becoming a hero was the same as Izuku's, the Symbol of Peace, All Might. However, their beliefs differ: Katsuki feels a hero should never stop fighting or give up, regardless of the threat they face, and that always winning is the mark of a true hero.
Quirk and Abilities
Explosion (爆破 Bakuha): Katsuki's sweat on his palms are nitroglycerin-like, and he can use it to create explosions. The more Katsuki sweats, the stronger his explosions become. So far, the signature use of his Quirk is through his hands; usually between punches or to shroud his fist with explosive energy. His most powerful Explosion so far (without the need of the Grenadier Bracers) was able to completely destroy Ochako's meteor rubble shower, knocking her down onto the ground at the same time and causing a shockwave that was felt throughout the stadium. Due to his extensive combat knowledge and creativity, this makes it a very deadly and versatile Quirk. One drawback of Katsuki's Quirk is that he is unable to use his explosions in areas filled with flammable gas as his explosions would ignite the gas and cause chaos.
- Blast Rush Turbo (爆速ターボ Bakusoku Tābo): Katsuki throws his hands backwards and then causes an explosion in his palms, to propel himself foward. This move can also be used to achieve a pseudo form of flight, as Katsuki used this move to fly over the giant robots during the Obstacle Race during the Sports Festival.
- Stun Grenade (閃光弾 Sutan Gurenēdo): Katsuki creates a sphere of light with his hands. The sphere of light implodes, causing an explosion around Katsuki, blinding anything in Katsuki's vicinity. This move was first used in Chapter 42.
- Howitzer Impact (榴弾砲着弾 Hauzā Inpakuto): Katsuki dashes into the air and creates two Explosions in his hands. While in the air, Katsuki spins himself around, building up momentum for his Explosions. After spinning himself around and gathering momentum for his Explosions, Katsuki fires an Explosive tornado at his opponent. This move was first used in Chapter 43.
Overall Abilities: Katsuki has shown to be one of the strongest students on Class 1-A. He was able to defeat Fumikage Tokoyami and Shouto Todoroki during the Sports Festival, people who are also considered to be quite strong (although they had disadvantages respectively in their fights against Katsuki but despite these limitations they still proved to be strong). Many notable Pro Heroes such as Shouta Aizawa and All Might have praised Katsuki's prowess; even the League of Villains have taken notice of Katsuki's strength and went as far as kidnapping him even if it meant losing members of the Vanguard Action Squad.
Enhanced Strength: Katsuki possesses an above average physical strength, as he was able to fight on par with Izuku even when the latter is using his Quirk. He was also able to pressure and overpower Shouto Todoroki, a powerful combatant, during their battle.
Keen Intellect: Katsuki has proven to be very smart and strategic, as he was able to figure out Kurogiri's Quirk weakness and Fumikage's weakness in a short period of time. Additionally, he quickly assessed which of the attacking villains in USJ was the most dangerous threat in the long term. Even Pro Heroes (such as All Might) have mentioned several times his great potential and battle-sense. Shouta Aizawa stated that in battle Katsuki shines his brightest.
Grenadier Bracers (籠手 Kote): An adjustment added to Katsuki's hero costume that stores his nitroglycerin-like sweat. Once filled he can pull the grenade pin in order to release a large blast. As shown when he fought Izuku in All Might's Heroes vs. Villains test. It has enough explosive power to destroy all parts of the building within its blast radius. This equipment was first used during the Battle Trial arc in Chapter 9.
- Katsuki's nickname is "Kacchan" (かっちゃん Kacchan), which was given by Izuku Midoriya when they were young.
- Katsuki loves spicy food and mountain climbing.
- Originally, Katsuki was supposed to be a natural born genius, a very kind and gentle character who spoke without thinking and unintentionally insulted others. The author, however, found this original draft to be boring and decided to make him an unpleasant character instead.
- Katsuki is student no.17 in Class 1-A.
- Katsuki ranked first during the Entrance Exam and third during the Quirk Apprehension Test.
- In the First Popularity Poll, Katsuki ranked 3rd.
- Katsuki's name is composed of "爆" (baku?) from "爆破" (bakuha lit. "explosion"?) and "勝" (ka(tsu)?) from "勝つ" (katsu lit. "to win"?).
- Katsuki ranked 3rd in Class 1-A's Grades
- (To Izuku Midoriya) "From here on, I..! From here on..! Y'hear me?! I'm gonna... beat you all! Enjoy your win. It'll never happen again! Dammit!"
- (To All Might) "Needless to say... I'll be a hero that surpasses even you!"
- (To Shouto Todoroki) "You'll regret making a fool of me! I'll freaking kill you! I'm taking the first to end all firsts! There's no point in winning against some half-assed punk! No point if I can't do better than Deku! So if you're not trying to win, get the hell outta my face! Why're you even here, you bastard?!"
- (To Izuku Midoriya) "Stop talking. I will win. That's... what heroes do."
- (To the League of Villains) "Can't stand morons like you who can't get to the damned point! Basically you're saying, 'we wanna cause trouble, be our pal!' What a joke! I've always admired All Might's triumphs. No matter what any of you jerks say... Nothing's ever gonna change that!"