Before becoming soldier for the Reiss family, Kenny Ackerman (Attack On Titan) was a ruthless serial killer in the capital of Wall Mitras, earning the name of Kenny the Ripper for slitting the throats of over hundred members of the Military Police Brigade.
Esdeath (Akame ga Kill) is terrifying and murderous sadist who enjoyed most brutal battles and ending people's lives in the most agonizing ways.
Despite his initial character, impression and appearance, Nagisa Shiota (Ansatsu Kyōshitsu) possesses a frighteningly massive amount of hidden bloodlust.
Knowing only solace through fighting and killing as many enemies as possible, Guts’ (Berserk) need to fight…
...was enough to drive
him to kill one hundred Chuder soldiers in a single night...
...multiple Midland guards...
…and after the events of the Eclipse, his need to kill manifested into his personal Inner Beast
, The Beast of Darkness
that urges him to continue on killing every last Apostle and seek revenge against the God Hand.
When taken over by his inner Hollow, Ichigo Kurosaki (Bleach) becomes a nigh-unstoppable killing machine.
According to Yhwach, the First Captains of the Gotei 13 (Bleach) were actually a brutal mob of killers.
Genryusai Yamamoto (Bleach) was once feared as a demon due to his ruthless leadership who even sacrificed his own subordinates and innocent lives to fufilled his goals.
Yachiru Unohana (Bleach) was feared as the most terrifying criminal of Soul Society due to her endless thirst for bloody battle.
Yhwach (Bleach) is a utterly ruthless and sadistic being, freely slaughtering enemy and ally alike just to further his own goals, and even looks down upon compassion and mercy.
Rei Ogami (Code:Breaker) ruthlessly killing evil while ignoring all pleas.
Light Yagami (Death Note) enjoys killing criminals using the Death Note which eventually turned him into a ruthless terrorist and a mass murder with a god complex.
Tyki Mikk (D.Gray-man) awakens, which instills in him a single-minded desire to kill Exorcists.
Freiza (Dragon Ball Z/Super)
Upon becoming a Super Saiyan 2, Son Gohan (Dragon Ball Z) became a merciless, sadistic killer...
...effortlessly killing each and every Cell Jr...
...and deliberately dragged out his fight with Cell to torture him.
Majin Vegeta (Dragon Ball Z)
Kid Buu (Dragon Ball Z) is a near-mindless killing machine who cares for nothing but wanton mass destruction. If he is not destroyed, Buu will not stop until everything in existence is wiped out.
While she has blue hair, Launch (Dragon Ball) is sweet and gentle. However whenever she sneezes, her hair turns blonde and Launch becomes a vicious psychopath.
Broly (Dragon Ball Z) is destructive, drove by Son Goku/Kakarot when they were infants.
Lucy (Elfen Lied) is a Diclonius driven by the DNA Voice to replace all non-horned humans on Earth.
Acnologia (Fairy Tail) is an extremely ruthless Dragon Slayer, having slaughtered countless Dragons to satisfy his thirst for revenge.
In order to fully control his Ankhseram Black Magic, Zeref Drageel (Fairy Tail) learnt to suppress his compassion and hardened his heart, becoming cold hearted enough to kill without mercy.
Future Rogue (Fairy Tail)
Eri Nakamura (From Common Job to Strongest) is extremely twisted and cruel, seeing all people as worthless trash. Her obsession with Kouki led her to plot a massacre by zombifying the Knights of Heiligh Kingdom and her Classmates into her undead puppets.
Already cruel and sadistic, Daisuke Hiyama (From Common Job Class to World's Strongest) was driven insane by jealousy to Hajime for Kaori's love, becoming murderous psychopath who assisted Eri in her massacre by killing the Knights of Heiligh Kingdom and Kaori to make her his undead sex slave.
Ruthless, cold and calculating, Yuno Gasai (Future Diary) is perhaps the world's greatest and deadliest Yandere.
Having suffered persecution for centuries due to his Immortality
, Utsuro (Gintama) developed multiple personalities that turned into serial killers and cold-blooded assassins, eventually becaming omnicidal.
Goblin Slayer (Goblin Slayer) is completely ruthless in hunting down goblins, to the point of massacring any goblins nest he can find…
…including children mercilessly to prevent them from becoming threats in future.
Cold & ruthless, Duke Togo (Golgo 13) will kill anyone or thing who gets between him and his target.
Hisoka Morow (Hunter X Hunter) has an insatiable love for spilling the blood of powerful fighters in combat and his enjoyment of extreme pain while doing so fuels his seemingly sadomasochistic desires.
Killua Zoldyck (Hunter X Hunter)
Inuyasha (InuYasha), when overcome by his demon blood, has a tremendously murderous intent.
Whether it was due being raised by his brutal, abusive father or being born evil, DIO Brando (JoJo's Bizarre Adventure)...
...showed a complete lack of restraint in his violence, and was prone to sadist murderous outbursts even as far as his childhood.
Despite his stern, no-nonsense exterior, Kars (JoJo's Bizarre Adventure Part II Battle Tendency) possesses a murderous and sadistic nature…
…massacring his entire race, including his parents, when they sought to execute him in order to maintain the natural order.
Lurking unnoticed in the town of Morioh for years, Yoshikage Kira (JoJo's Bizarre Adventure Part IV Diamonds are Unbreakable) is a paraphilic serial killer.
Diavolo (JoJo's Bizarre Adventure Part V/5: Golden Wind/Vento Aureo)
At the young age of 12, Bruno Bucciarati (JoJo's Bizarre Adventure Part V/5: Golden Wind/Vento Aureo) ruthlessly and coldly murdered gangsters aiming to take his father's life.
Possibly inheriting his father DIO Brando's mentally, Giorno Giovana (JoJo's Bizarre Adventure Part V/5: Golden Wind/Vento Aureo) has shown his ability to kill when it's absolutely necessary or the last resort.
Cioccolata and Secco (JoJo's Bizarre Adventure Part V/5: Golden Wind/Vento Aureo)
Shin of the Hi Shin Unit (Kingdom)
Ou Ki, the Monsterous Bird of Qin (Kingdom)
Responsible for the deaths of over 890,000 enemy soldiers in his military career, Haku Ki (Kingdom) was the cruelest member of the Six Great Generals of Qin...
...demonstrating his ruthlessness when he ordered the deaths of over 400,000 captive Zhao soldiers...
...by burying them alive.
Before becoming a General for the State of Qin, Kan Ki (Kingdom) was a mountain bandit with a penchant for decapitation as he would personally behead every person in any city or village he conquered, which earned him the moniker The Beheader.
Ri Boku of Zhao's Three Great Heavens (Kingdom)
Hou Ken of Zhao's Three Great Heveans (Kingdom)
Rin Ko of the Four Heavenly Kings (Kingdom)
After witnessing the death of his entire family during the Battle for Chou Hei as a child, Man Goku (Kingdom) became obsessed with venegnce against the State of Qin…
…repeatedly commiting vicious atrocities on its citizens during his career as a general which earned him the epithet, General of Assault.
Kou Yoku of the Thunder (Kingdom)
Raised as an assassin, Kyou Kai (Kingdom) shows absolutely no mercy towards her enemies.
Raised as a Shiyuu assassin, Yuu Ren (Kingdom) is ruthlessly dedicated towards her clan, to point of dutifully commiting sororicide to finalize her training.
Earl Shi of the Wei Fire Dragons (Kingdom)
Gai Mou of the Wei Fire Dragons (Kingdom)
Ba Tei of Rigan (Kingdom)
Known for their excessive sadism and "Interrogation" skills, The Saki Clan (Kingdom) are torture specialists within the Kanki Army...
...shocking capable Zhao soldiers with their skills in psychological warefare after turning the civilians of Koku You Hills into a human arc.
Due to his father corrupt teachings, Felix Aaron Thenardier (Madan no Ou to Vanadis)…
…grew up to become an extremely ruthless and brutal tyrant.
Driven insane by her hatred for King Solomon, Arba (Magi the Labyrinth of Magic) became immensely sadistic and brutal willingly to kill even her own descendants for both world annhilation and sadistic entertainment.
As a creature born from evil energy, Orb (Marchen Awakens Romance) will kill anyone he wants without even a remote sense of remorse.
Influenced by the Orb, Diana (Marchen Awakens Romance) has grown into a power-hungry woman who will show no mercy to those who stand in her way of becoming the queen of MÄR Heaven.
Despite his charms, Phantom (Marchen Awakens Romance) is the mad leader of the evil Chess Pieces army, who accepted the Zombie Tattoo to become immortal. Looking down on the mortality of the world, Phantom will stop at nothing to wipe out all of humanity.
While under the influence of the Zombie Tattoo, Alviss (Marchen Awakens Romance) entered a berserk state where he wouldn't hesitate to kill his own allies.
Peta (Marchen Awakens Romance) shares Phantom’s ideals that humans are trash and feels no regret for the pain he causes others. He once even wiped out an entire fortress, not only killing enemy warriors, but innocent women and children as well.
After killing the ones who constantly bullied him as a child, Halloween (Marchen Awakens Romance) learned the pleasure of tormenting others. He grew up to join the Chess Pieces as one of their strongest and most sadistic soldiers.
After acquiring the power to get revenge on the men who tortured her, Chimera (Marchen Awakens Romance) decided to abandon her humanity as well as her original name, Eileen. Becoming known as Chimera, a monster who enjoys giving pain rather than receiving it.
Weasel’s (Marchen Awakens Romance) Guardian ÄRM, Yggdrasil is a tree that grows by absorbing the pain and suffering her master causes others.
Candice (Marchen Awakens Romance) was a sadistic army commander who showed no mercy in battle. Her bloodlust only increased when she defected to join the evil Chess Pieces.
When Rapunzel and Girom’s (Marchen Awakens Romance) father died of a disease, their mother became demented. She denied them of everything, even food and whipped them each day. This abuse would later seep into the siblings giving them sadistic personalities.
Because of his ugly face, Kouga (Marchen Awakens Romance) has been treated miserably ever since he was a boy. The abuse and humiliation drove him into madness. Ever since he joined the Chess Pieces he's had a tendency to kill those around him, especially handsome boys.
Pinocchion (Marchen Awakens Romance) is a doll brought to life with dark magic. In addition to being a liar, Pinocchion is a sociopath who won't hesitate to kill to impress the Chess Pieces’ Queen.
Orco (Marchen Awakens Romance) is a simpleminded but sadistic Bishop class Chess Piece. He takes pleasure in destroying buildings and along with Girom, was the one who demolished the beautiful city of Vestry.
Maira (Marchen Awakens Romance) was once nothing but a cowardly Pawn-class Chess Piece. One day however he discovered Vaqua, a Guardian ÄRM with the power to absorb others. Since then, Maira has found pleasure in using Vaqua to absorb as many people as possible.
After the Chess Pieces threw the world of Mär Heaven into chaos, the Zonnens (Marchen Awakens Romance) indulged in abominable acts of abduction, decimation and destruction and beheld the ravage as a sight of beauty. Even the Chess commander, Phantom was revolted by the group's barbarity.
Saturn (Marchen Awakens Romance) is the leader of the barbaric Zonnens. Despite his Rook earring, Saturn possesses both the power and viciousness of a Knight-class Chess Piece. He even considers being called a monster as a compliment and prefers to torture his opponents before he kills them.
Redrun (Medabots) is a Kilobot programmed to fight those she senses as worthy opponents. Even after their defeated, she refuses to end her assault until they're completely destroyed.
Kei Munakata's (Medaka Box) Abnormality is his instinctive desire to kill. His instinctual ability as a killer is so great that he is capable of inflicting fatal injuries with his bare hands.
Hero Killer Stain's (My Hero Academia) desire to kill "fake heroes" can frighten even the most experienced of heroes with his aura alone.
Himiko Toga (My Hero Academia) has such a strong killing instinct, she can savagely murder with a cutesy attitude.
All For One (My Hero Academia) will kill anyone who stands between him and his ambitions.
Holding the title of a Demon, Zabuza Momochi (Naruto) slaughtered over 100 Academy students without pause or hesitation as a child.
Before being defeated by Naruto Uzumaki, Gaara (Naruto) was a near psychotic killer, especially when Shukaku influenced him.
Shukaku (Naruto) is a very bloodthirsty monster tanuki, and even more so when under the full moon.
The now extinct Kaguya Clan (Naruto) were known for their savagery and lust for bloodshed and war.
Deranged with revenge and hatred towards Konoha/Leaf Village, Sasuke Uchiha (Naruto) become a completely amoral murderer…
…ruthlessly killing a great number of Samurai…
…and stabbing through his fellow Taka, Karin in order to kill Danzo Shimura.
When his enzymes take over, Jūgo (Naruto) becomes temporarily insane with killing intent.
Hardened by a war-torn childhood and deaths of his brothers, Madara Uchiha (Naruto) became completely apathetic and disillusioned towards reality, and seeks to replace it with a dream world in the Infinite Tsukuyomi regardless of how many people must die....
...even if it means killing one of his last remaining descendents.
After the death of Rin Nohara, Obito Uchiha (Naruto) became resentful towards reality which he sees as living hell, and thus has no qualms massacring ninjas of the Hidden Leaf, even causing the death of his own teacher.
Driven by anger and despair over the death of his best friend Yahiko, Nagato (Naruto) became completely merciless, described to have a cold heart of steel renaming himself Pain.
Possessing a dangerously violent temper, Kakuzu (Naruto) will ruthlessly killed anyone who displeased him.
Hardened by his parents's death and the corrupt militaristic teachings of the Hidden Sand, Sasori (Naruto) has become devoid of compassion and empathy, and saw people as nothing more than materials to create organic puppets.
Hidan (Naruto) is a religious fanatic to ritual killing by painfully sacrificing people in the name of Jashin
Even though he cared for his family deeply, Itachi Uchiha (Naruto) killed his entire clan sparing only his little brother, Sasuke.
Though an honorable swordsman samurai with a heart of gold, Roronoa Zoro (One Piece) is also capable of being completely ruthless and merciless towards his enemies and opponents.
When Shiliew of the Rain (One Piece) was the Head Jailer of Impel Down, he ruthlessly killed any prisoner he wanted.
The Fleet Admiral of the Marines, Sakazuki/Akainu (One Piece) is deeply feared by both pirates and marines alike due to his complete ruthlessness in serving Absolute Justice.
When Arlong (One Piece) is angry, he enters a killing mode of sort, befitting that of a shark.
Hody Jones (One Piece) inherited the fishman's hatred for humanity since he was taught to do so. He and his crew harm their minions and the ones who are friendly to humans.
Donquixote Doflamingo (One Piece) is a sadistic tyrant described by his own brother as a demon who was born evil. Due to childhood trauma, he swore revenge against the Celestial Dragons by vowing to destroy the world they ruled over, massacring countless people including Dressrossa citizens and killing his own father and brother.
Caesar Clown (One Piece) is a mad scientist with a reputation of building weapons to murder people and no problem killing his own henchmen just to demonstrate his inventions.
Pica (One Piece) is very sensitive about his high-pitched voice. If someone so much as snickers, he will violently slaughter them living nothing but red paste.
Due to being constantly ridiculed during his years as a slave, Gild Tesoro (One Piece: Flim Gold) will kill anyone who dares to laugh without his permission.
Despite his flamboyant and flashy attitude, Dellinger (One Piece) becomes sadistic and bloodthirsty because of his own heritage of Fighting Fish fishman.
Gladius (One Piece) is feared for his very short temper which often gets the best of him. If someone offends him or his captain, Doflamingo in even the slightest way Gladius will use his powers to blow them up.
Caribou (One Piece) is an insane pirate known for slaughtering Marines. His sadistic nature leads to him using brutal ways to kill people such as burying them alive or suffocating them with his powers.
Cavendish (One Piece) possesses a dual personality, Hakuba, who is ruthless in slashing down everyone in range whenever Cavendish falls asleep.
Charlotte "Big Mom" Linlin (One Piece) is immensely brutal, ruthlessly killing anyone, even her own children. What she desires above all is sweets and will destroy entire countries should they fail to give it to her. Invitees who refused to attend her tea parties will have their loved ones decapitated as presents.
Due their mother's influence, most of the Charlotte Family (One Piece) are just as murderous and ruthless as their tyrannical captain...
...one of the most sadistic members of the Charlotte Family, Charlotte Perosperos will often cannibalize people by turning them into candy structures...
...fiercely loyal to his mother and siblings, Charlotte Katakuri will ruthlessly kill anyone who threatens his family...
...due to his absolute loyalty to his mother, Charlotte Oven is even more ruthless than his brother Katakuri, burning alive anyone who dares to opposed Big Mom, having no sympathy towards those his mother has victimized...
...like his brothers and sisters, Charlotte Daifuku has the utmost loyalty to his mother which drives his ruthlessness to kill without mercy and remorse, as he prepares to execute Sanji to start her Vinsmoke Assasination plans...
...Charlotte Brulee enjoys killing and disfiguring attractive girls...
...living to her nickname of Demon Lady, Charlotte Amande believes there is no meaning in slaughter if the victims can't experience the pain. Demonstrating as she slowly sliced King Baum, giving the giant tree an agonizing death...
...having been viciously bullied and scorned for her third eye as a child, Charlotte Pudding…
…grew up to be very cruel and sadistic...
The Vinsmoke Family (One Piece) are a royal family of prestigious Underworld assassins and mercenaries.
Don Krieg (One Piece) is a ruthless pirate admiral known for his underhanded tactics and mass murders. His dishonesty and brutal nature earned him the alias "Foul Play Krieg".
Kaido (One Piece) is a ruthless warrior who does not make himself open to negotiation or excuses and won't hesitate to kill should someone fail to comply with his demands.
Jack the Drought (One Piece) has an unreasonable nature and always resorts to bloodshed, including to attacking children and the elderly and has a love for causing destruction, even when there is no real benefit to it.
Rob Lucci (One Piece) is a heartless killing machine and the strongest member in the history of CP9…
…even at the age of 13, he slaughtered over 500 kingdom soldiers for surrendering to pirates…
…and was especially bloodthirsty in a battle, due to his Neko Neko no Mi: Model, Leopard being a Carnivorous Zoan type. Evening going so far as turn into a full leopard and maul his opponent.
Thinking of himself as God because of his Logia Devil Fruit powers, Enel (One Piece) believes he has the right to kill anyone he wants and is one of the most sadistic, egotistical, and uncaring characters of the series. He even destroyed his entire home, Birkia just because he felt like it.
Kuro (One Piece) shows absolutely no remorse in killing his subordinates.
A bloodthirsty psychopath, Capone Luke "Gang" Bege (One Piece) is infamous in the Underworld for attacking mafia leaders simply for the sake of causing blood smeared chaos. His lust for bloodshed is so extreme, that he even desires to assassinate the Yonko Big Mom.
The Deep Sea King (One-Punch Man) was a sadistic monster who enjoy causing pain to others and starting fights.
Garo/Garou (One-Punch Man), the Human Monster enjoys hunting the heroes viciously.
Zahlenschwestern (Phantom of Inferno) are elite brainwashed female assassins of scythe master. They were created using the fighting data of Ein, Zwei and Dre…
…Zwei and Ein were taken by scythe master because of their natural killing instincts. They were brainwashed and trained to eliminate any threat to inferno. Zwei's eye color change when his killer instincts are activated.
Akua Shuzen (Rosario + Vampire) giving her signature deranged look that is filled with killing intent.
A sadistic creature, Demon Eyes Kyo (Samurai Deeper Kyo) loves to kill his enemies, delighting in their deaths.
Giriko (Soul Eater) can overwhelm his opponents with sheer raw power of the blood-lust built up over 800 years.
Maruss (Zatch Bell!) is a short tempered mamodo who finds pleasure in taking his anger out on innocent people. Due to Tia getting away from him so many times, he threatened that once he burned her book he would attack her bookkeeper's concert.
Zofis (Zatch Bell!) is a heartless mamodo who only cares about becoming king. After brainwashing the sweet Koko into becoming his bookkeeper, Zofis forced her to burn down her village.
Koko (Zatch Bell!) became sadistic because of Zofis’ mind control and enjoys hurting people just as much as her mamodo does.
Clear Note (Zatch Bell!) believes killing mamodo is the very reason for his birth and only wants to become king so he can bring genocide upon his people.
Despite being an infant, Clear Note's bookkeeper, Vino (Zatch Bell!) enjoys helping his mamodo and gets sadistic pleasure in hurting people and mamodo alike.