Shonen heroes are typically morally righteous characters who always do the right thing. Yet, many situations call for more ruthless champions. When battles get tough, and decisions need to be made, many cold-hearted heroes step in to take the plunge and do what is necessary to win.

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Though they are not as prolific as compassionate protagonists, these ruthless shonen heroes know how to get the job done. Some of these heroes are merciless in battle, while others are cold-hearted by nature. Even so, all of these particular shonen heroes will do whatever it takes to get what they want and won't back down — no matter the cost.

10 Saya Takagi Is Cold To Everyone But Alice

High School Of The Dead

Saya Takagi pointing in High School of the Dead.

Saya Takagi is a calculating student among those fighting zombies in High School of the Dead. Her cold demeanor and unparalleled genius make her a sharp but necessary part of the team.

Although Takagi is curt with almost everyone, she does have a soft spot for the youngest member, Alice Maresato. Alice is merely seven years old and can't really use weapons yet. Takagi shuts down anyone who tries to tarnish Alice's innocence, making her a ruthless, but protective classmate to have.

9 Kyo Sohma Wants To Prove His Strength

Fruits Basket

Kyo Sohma looking angry in Fruits Basket and shaking his fist as Tohru tries to calm him.

Kyo Sohma is the reviled Cat Zodiac in the mysterious Sohma family. As such, Kyo trains desperately to prove his worth. He regularly picks fights with his cousin Yuki (the Rat) and verbally tears down anyone he thinks is acting weak in the anime Fruits Basket.

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Although Kyo is hated by his family, he never gives up and relentlessly tries to improve himself. Although he never beats Yuki in a physical fight, Kyo never pulls any punches. Kyo is a ruthless fighter who will do anything to climb his way into his family's good graces.

8 Katsuki Bakugo Will Fight Anyone Willing

My Hero Academia

Katsuki Bakugo from My Hero Academia grinning in battle

Katsuki Bakugo is a bombastic student in Class 1-A from My Hero Academia. Although he is young, Bakugo has developed a devastating thirst to show everyone how talented he is. As such, Bakugo is always ready to fight any willing and worthy opponent he comes up against.

Bakugo's temper highlights his mercilessness in battle. He regularly yells at people for not knowing things he knows how to do and seldom has a kind word to say. Whether on the battlefield or in class, Bakugo gives everything he has to prove he is the best.

7 Ryuko Matoi Becomes Both Human & Life Fiber

Kill la Kill

Ryuki Matoi from Kill la Kill.

Ryuko Matoi begins Kill la Kill on a crusade to find the person who murdered her father and avenge his death. However, once she meets the Kamui, Senketsu, Ryuko bonds with him and does anything she can to rid the world of Life Fibers — including becoming part of them herself.

Ryuko does not care what happens to her so long as she defeats Ragyo Kiryuin and her Life Fiber army. Since Ryuko was an infant, she became half-Life Fiber and half-human — a trait she uses to magnificent effect in the show's final act. Ryuko shows that she would travel any length to avenge her father and free the world from clothes.

6 Nobara Kugisaki Uses Her Own Body Against Her Enemies

Jujutsu Kaisen

Nobara Kugisaki using her Straw Doll technique on herself in Jujutsu Kaisen

Nobara Kugisaki is one of the Sorcerers in training at Jujutsu High in Jujutsu Kaisen. Although she is typically bubbly and fun-loving, her demeanor changes when she is on the battlefield.

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Kugisaki's Straw Doll Cursed Technique is fearsome. With a straw doll and her nails, she can torment Cursed Spirits into submission. However, when one of them has her on the ropes, Kugisaki uses her own body to perform her Cursed Technique. Without a second thought, she hammers nails into her arm to subdue her enemy. With this one display of grit, Kugisaki proves that she would do anything to win.

5 Tengen Uzui Shows No Mercy To Demons

Demon Slayer

Tengen Uzui poses with his weapons while grinning

Tengen Uzui is a shinobi and a Hashira in Demon Slayer. His propensity for big flashy moves and his command of sound have earned him the title of Sound Hashira. However, Tengen is also known for his distaste and impatience for demons.

With one fell swoop, Tengen lops off demons' heads without pomp or circumstance. Even when he initially faces the Kizuki Daki, he barely lets her get a word in before her head rolls off of her body. Although it does not kill her, Tengen later cements his ruthlessness as he helps to slay Gyutaro despite his devastating injuries.

4 Yor Forger Cuts People Down With Ease

Spy x Family

Yor Forger from Spy x Family dressed as the Thorn Princess.

Since she was a teen, Spy x Family's Yor Forger has been an assassin. With nearly a decade of work under her belt, Yor has honed her deadly skills to a fine point. She can mercilessly end the lives of a room full of grown men without so much as breaking a sweat.

In addition to her nightly work, Yor is also ruthless in her everyday life. Whenever her adopted daughter, Anya, is threatened or mistreated, Yor brutally attacks the aggressor without question. Even if the slight is only perceived on Yor's part, she will destroy anyone who treats her daughter with anything less than kindness and respect in Spy x Family.

3 Olivier Mira Armstrong Commands Fort Briggs

Fullmetal Alchemist: Brotherhood

Olivier Mira Armstrong from Fullmetal Alchemist: Brotherhood.

Major General Olivier Mira Armstrong is the strong and cold commander of Fort Briggs in Fullmetal Alchemist: Brotherhood. As the leader of the Northern stronghold of Amestris, Olivier is known to be as hard and unforgiving as the piercing cold they endure.

Olivier's most ruthless act occurs when she covers a criminal officer in cement. But she is also merciless with her own family. She had an all-out brawl with her younger brother, Alex Louis, and won — despite his impressive physique. Yet, despite all of this, Olivier is much beloved by her subordinates, who would blindly follow her into any battle she deems worthy of her time.

2 Louis Forsakes His Herbivore Peers

Beastars

Louis from Beastars.

Among all the Cherryton students in Beastars, Louis is the best and brightest. His regal presence and outwardly amiable persona make him a prime candidate to become the next Beastar. However, behind closed doors, Louis is less a champion of the people and more like a conniving and desperate individual who will do anything to gain his coveted role.

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Even after Louis gives up on becoming the next Beastar, he somehow finds himself at the head of a Lion crime syndicate. To prove himself a worthy leader, Louis even eats herbivore meat — despite being an herbivore himself. He also lets Legoshi eat one of his legs to gain enough power to fight Riz. Louis's dedication to his leadership positions and his willingness to win at any cost make him one of the most ruthless shonen heroes.

1 Akira Obliterates His Friend's Killers

Devilman Crybaby

Akira transforms into a demon in Devilman Crybaby.

When an encounter with real demons goes wrong, Akira Fudo finds himself becoming one of them in Devilman Crybaby. As a half-human, half-demon hybrid, Akira fights against his demon brethren to save humanity — that is, until humanity turns against him.

Upon seeing his friend's remains being paraded around on pikes by an angry human mob, Akira erupts with rage and decimates everyone in the vicinity. In Akira's mind, there are no second chances when his friends and family have been crossed — especially in the case of Miki Makimura.

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