Jadzia Dax: Worf, I don't think you can tell someone's going to kill you by looking at them.
Worf: A Klingon can. It is an instinct. The ability to look someone in the eyes and see the decision to kill.
Particularly common in Eastern works is the idea that when someone intends to inflict pain or death, their "Killing Intent" can be felt as a slight pressure or chill, even to people unaware of their presence. The effect is amplified if you look into their eyes, or if they want to hurt you in particular. Trained and vigilant warriors generally radiate low levels of Killing Intent at all times, and anyone who constantly radiates high levels of Killing Intent is either evil or obsessed with combat (and may feel kinship towards other people who possess it). There's generally a noticeable difference between "hot-blooded" and "cold-blooded" Killing Intent too. Sometimes this is considered a form of Ki, or has an effect on Ki.
While most people can only detect Killing Intent subconsciously, people who have enough combat experience (or are just perceptive) can notice it so well that it borders on Spider-Sense or Detect Evil. Likewise, some particularly vicious characters hone their Killing Intent to the point where it can leave people nearby paralysed with fear or even inflict hallucinations. In either case this will be treated as a mundane skill and not a supernatural ability, and can easily show up without comment in works which don't otherwise have any fantastic elements. Some people will even tell you it's possible in Real Life.note
While having some degree of Killing Intent is normally required to fight effectively, sometimes a character will be able to attack without exuding any Killing Intent at all (through Lack of Empathy, controlling their emotions or even spacing out while fighting), making them an unpredictable combatant or even a Hero Killer.
In some works Killing Intent can be used as a rough way to measure Power Levels, as someone with sufficient willpower to resist an enemy's Killing Intent will necessarily be at least as strong as them.
Since it's hard to depict a sixth sense through a visual medium, Killing Intent is often represented in Anime and Manga by Art Shift towards a more serious style, or even a Battle Aura (the metaphorical version), though this has become less common over time. When Killing Intent is considered a form of (or augments) Ki, it can be represented by a non-metaphorical aura.
The Japanese term for this is sakki (殺気note ), which is primarily used by practitioners of Ninjutsu; "Killing Intent" is the most literal translation.
Compare Detect Evil and Allergic to Evil, which can overlap with this trope if a character's sensitivity to Killing Intent is enhanced by supernatural means. Can be used as a justification for Spider-Sense, The Force Is Strong with This One, and Kung-Fu Clairvoyance. See also Death Glare and Ki.
- In Naruto most experienced ninjas can explicitly use killing intent, and using it to paralyse enemies is a recognised strategy (most famously used by Orochimaru, and the first clash between Zabuza and Kakashi). This ability explicitly does not use chakra.
- In Bleach the force of Kenpachi Zaraki's killing intent causes Ichigo to hallucinate that he is being stabbed as he approaches.
- The martial artists in Ranma ½ can sense if someone is about to attack them. Ranma is so good, he sometimes dodges attacks in his sleep. Unfortunately for Ryōga, his "danger sense" is also affected by his terrible sense of direction.
- Present for one moment of JoJo's Bizarre Adventure: Battle Tendency, when LisaLisa is about to fight Kars, and notes that she can't detect his Killing Intent. Despite his earlier claims, he never intended to fight her fairly for the Macguffin, and instead has a mook ambush her mid fight while he hides, so he can attack her from behind, claim the Macguffin, then sic his zombie army on Joseph.
- In One Piece, this is one of the functions of Haki: people with Conqueror's Haki are able to One-Hit KO scores of Mooks through the strength of their ambition. Zoro does this as well. His "Kiki Kyutoryu: Asura" is said by Kaku to be a illusory manifestation of his killing intent.
- In Lone Wolf and Cub, every half-way decent martial artist possesses this ability. One memorable story played with the trope, when Ogami Ittō's target was a monk whose lack of killing intent was so strong that it would reflect the intent of attackers back on themselves; not even Ogami could overcome it at first. After meditating and learning how to kill without emitting killing intent, Ogami returns to finish the job. (The priest compliments Ittō on his accomplishment after being split from scalp to sternum.)
- Rurouni Kenshin uses this, while leaving it ambiguous whether it's based on Ki or just body language. The only time Kenshin had significant trouble fighting against someone of a (slightly) lower skill level was Soujirou, whose combination of being a Stepford Smiler and super speedster made him both difficult to read and difficult to react to. Additionally, swordsmen of high enough caliber generate Battle Aura that can cause minor destruction.
- In Fullmetal Alchemist this is how Riza figures out that Selim Bradley is actually the homunculus Pride.
- Later, Kimblee figures out he's being lured into a trap because he can feel the killing intent of the snipers nearby.
- One of the many appliances of Nen in Hunter × Hunter. It's worth noting that people unprotected by their own aura could potentially die or suffer serious psychological trauma if they were to be attacked by a strong enough killing intent.
- For a split second in Murciélago, right before Kuroko gets serious with fighting Yukari, Yukari sees a vision of a multi-armed skeleton tangled around her with a scythe around her neck and Kuroko's trademark giant tongue sticking out of its mouth.
- Parodied in Busou Shinki, where Clara becomes alarmed and claims that she's "never felt so much killing intent"... shortly before a letter falls on her head (she's 15cm tall, but still).
- A silly example in One-Punch Man, where Asura Rhino's combat instincts cause him to see the protagonist with heavy shading and surrounded by dark flames... but he's still drawn in a simple style and with a baffled expression.
- Martial artists in Angel Densetsu are constantly amazed at being unable to sense Kitano's killing intent. They always assume he is so skilled that he can hide this, instead of realizing he has less anger than an angel.
- In Monster, the eponymous Serial Killer is so evil that he can terrify people just by being in the same part of the building.◊
- In Kenichi: The Mightiest Disciple, every martial artist senses or projects killing intent at one time or another. On at least one occasion, Sakaki has blown away an entire room of people. And with disciple-level fighters it can be used to make the opponent lock up and break their focus.
- In Basilisk the Dojitsu is an ability that can turn attacker's killing intent back on themselves, thus violently attacking themselves.
- Toriko has killing intent manifest as monstrous Animal Battle Auras known as "Intimidations".
- Fist of the North Star:
- Kenshiro manifests one of these which freaks out a Fang Clan Giant Mook, a nearly feral beast who goes into a panic when he senses Kenshiro's sheer badassery and intent to wipe out the entire Fang Clan.
- In addition, this was used as a final test to determine who would be the successor of Hokuto Shinken. The test involved Kenshiro and Raoh coming face-to-face with a tiger. When the tiger backs away from Ken, Raoh takes this as a sign that the tiger thinks Ken is too weak and then kills him. In truth, the reason the tiger backed away from Ken was because he sensed so much power and killing intent radiating from him in comparison to Raoh that he feared for his own life.
- Nagisa from Assassination Classroom can freely intimidate or paralyze his opponents by emitting killing intent. He once used it, along with a single (theoretically nonthreatening) sentence and a calm smile, to send middle-school bullies home in tears; he's also used it in combat to scare the living daylights out of elite, trained government special ops soldiers. For the record, Nagisa is a small, kindhearted, fairly unremarkable middle school student in a bottom-rank class, and is so physically dainty that he's been mistaken for a girl several times. It should be noted that his killing intention is more of a natural talent. It is commented that he is born with talent at the wrong era. Had time been different, he would have been an assassin without equal.
- Dragonball Super: Beerus says that he has a refined ability to detect a person's killing intent (which is distinct from ki in general), as part of his powerset as the God of Destruction. He uses this to judge that Zamasu truly does intend to kill his mentor Gowasu, though he doesn't take the killing intent as proof and confirms his suspicions before taking action.
- Lyrical Nanoha:
- In Magical Record Lyrical Nanoha FORCE, when the Special Duty Section 6 are arresting Hades Vandein, his killing intent is so strong that everyone sees a hallucination how he slices Teana down. And this guy always pretends to be an innocent citizen.
- Chapter 45 of Magical Girl Lyrical Nanoha Vivid has Micaiah deliberately emanating this even though she's just attacking with a practice sword so she could bring out the depressed Sieglinde's Black Jeremiah side as a lead-in to her pep talk for the latter.
- Deconstructed in Psycho-Pass. Having a Lack of Empathy is illegal, and can lock you out of most jobs... but if Lack of Empathy upgrades to Killing Intent, the cops gain instant authorization to use lethal force with no repercussions or oversight. And an adrenaline rush counts as Killing Intent, regardless of why you're having an adrenaline rush, which often leads cops to execute the people they just saved from dangerous murderers.
- This is the implied reason Bando from Elfen Lied is able to sense and predict Lucy's vectors even when he has no prior experience (or even knowledge) of what a Diclonius is capable of: Lucy's immense hatred for humanity and desire to wipe them out bleeds into her vectors, which are otherwise invisible and selectively-tangible. Bando can't see her vectors directly, but due to his combat training and own love of life-and-death combat, he can get a sense of when and where Lucy's attacks are coming from.
- Shows up repeatedly in Vinland Saga. The most notable example is probably when Thorkell gets hyped for a fight and his opponent visualizes his killing intent thusly.◊Said opponent never even gets to lift his weapon; his mind breaks from the killing intent and he spends the rest of the series as a vegetable.
- In My Hero Academia Stain shows evidence of this after being captured by Midoriya, Iida, and Todoroki during the Field Training Arc - he escapes, kills the Nomu trying to abduct Midoriya, and declares that the only hero worthy of killing him is All Might. Even Endeavor, the #2 Hero, is frozen in his tracks during this declaration. The anime represents this by having black fog with a reddish tint envelop everyone present, with glowing red eyes appearing over them as Stain finishes his speech. Note, this character already had a different ability established, which means this wasn't a power. He made everyone present freeze with utter terror from sheer force of will.
- Played for Laughs in Tomo-chan Is a Girl!, where Misaki is told that he can't match hardcore martial artists like Tomo and Junichiro because he's such a Nice Guy and is utterly lacking in killing intent. Then comes an incident where he mistakenly thinks that some thugs sexually assaulted his Love Interest Carol and gets so pissed off that even working together, Tomo and Jun have a hard time keeping him from actually killing the thugs. Afterwards Tomo's father (who's also their martial arts instructor) notices the change in Misaki and says he's worth training now.
- In Infinity, Lindy invokes Dissonant Serenity after Fate is injured so as to focus on arresting the person responsible, but her seething Mama Bear rage still ends up leaking through her otherwise cheery demeanor, terrifying poor Amy.
- In the work Strandpiel by A.A. Pessimal, eight-year old Ruth Smith-Rhodes-Stibbons has a terrifying "dream" where she revisits a desperate fight from many years before she was born; she is forced, by a malevolent external agency, to spectate the depserate fight her mother hadnote with a brual psychopathic killer intent on murder. Despite being terrified, Ruth — who has a streak of magic inherited from her father, Ponder Stibbons - realises everybody has an aura and can be seen as enclosed in a halo of coloured light. A gifted artist, she resolves to try and paint this later. Ruth watches as the angry and evil colours surrounding the killer gather themselves. And then send out lightning flashes of scarlet light aimed at that part of her mother where her unborn sister is. She also sees her mother's Battle Aura put out everything it can to deflect this. She realises, then, that fights are not just conducted on the physical level with swords. Being the daughter of an Assassin, she grasps this too.
- In Kung Fu Hustle, Sing is sent to retrieve The Beast near the end of the movie. When he ends up right outside the room The Beast is in, he hallucinates a wave of blood bursting through the door Shining-style.
- In Hero, the emperor keeps a number of candles between himself and any visitors allowed to come within a hundred paces, claiming that the flames are disturbed by "murderous intent" (all of them blowing towards the emperor when Nameless is thinking of killing him, and then blowing in random directions when his resolve wavers). No sort of magical explanation is given for this, and Nameless' unquestioning acceptance of it suggests that he is familiar with the idea, presumably making it a variation of this trope, rather than a separate sort of Detect Evil magic.
- In the live-action adaptation of Rurouni Kenshin, Jin-e can stop people from breathing by looking into their eyes. He explicitly states that it's not supernatural, despite the fact that it can supposedly only be broken by killing Jin-e.
- In Rogue One: A Star Wars Story, Chirrut, a blind monk that was once a guardian of a Jedi temple and may or may not be Force-sensitive asks if Captain Andor has the face of a killer. His colleague Baze said he doesn't; he has a kind face, the face of a friend. Chirrut says that the Dark Side of the Force stirs around those who have intent to kill, and Jyn (with added observation by K2S0 that his rifle was in Sniper configuration) deduces that Andor intends to assassinate her father.
- Nico di Angelo demonstrates a weaponized version of this in the last book of Heroes of Olympus. When someone threatens to have one of his friends executed, he strips him of his identity and sends him to the Fields of Punishment through willpower alone.
- In Full Metal Panic!, Sōsuke's past as a child soldier has given him the ability to sense killing intent, which he uses to set traps for assassins targeting him. This was also used to torment him. One of Mithril's agents would observe him via the scope of a rifle, and find that Sōsuke actually got visually agitated when he did this. It's implied that much of Sōsuke's misbehavior in school is caused by him sensing the agent's killing intent without being able to tell where it's coming from, causing him to lash out against people nearby.
- Sword Art Online refers to the ability to sense killing intent from monsters in the game as "Hypersense", which may or may not actually exist.
- In Overlord, Sebas can control his Killing Intent with incredible strength and precision, to the point where he can stare into a group of hardened warriors and reduce one of them to a gibbering wreck without alerting the others. Normal people exposed to his Killing Intent could literally die of fright. At one point Sebas even uses this as a form of Training from Hell, teaching Climb a "mental overclock" ability by having him experience what it's like to be a hair away from death.
- Lina Inverse of Slayers has been known to use this to tell when somebody's sneaking up behind her in a fight. Gourry and Zelgadiss may also be capable of it - they've been known to react to attacks they couldn't have seen coming.
- In The Spirit Thief, people who are very good at killing can identify others like them upon looking at them, and sense their desire to kill. Josef is using it as a Spider-Sense of sorts, telling him when to treat a fight seriously.
- A Practical Guide To Evil doesn't name it as such, but Named can create an aura like this by flaring their power. As for what happens if you threaten to steal Ranger's fun...
The blade did not move, and neither did the hand that held it. And yet for a heartbeat I felt like my throat had been cut, like blood was gushing out. The intent had been so strong it had almost become a fact.
- In A Certain Magical Index, Vento of the Front's "Divine Punishment" causes anyone in the world who aims hostility at her to be knocked unconscious unless protected by powerful magic. Amata Kihara is immune to its effects due to being a Sociopath who can murder people without feeling any hostility towards them at all, comparing it to pulling up weeds.
- In one episode of Lie to Me, the Lightman group try to use their observational abilities to find an assassin by detecting his or her Killing Intent. The nature of the Lightman group's abilities means that they have to see the person's face for detection. Played with at one point. Lightman thinks someone has murderous intent and is planning to kill someone else, but it is actually suicidal intent. They manage to stop her before she goes through with it. Just because you have killing intent doesn't mean you're planning to kill another.
- In Star Trek: Deep Space Nine, Worf once states that Klingons can see murderous or violent intent in a person's eyes.
- Dungeons & Dragons 3.5 has the detect hostile intent psionic power. While active you can sense the presence of people with violence on their minds, are immune to surprise attacks (unless the attackers' minds are somehow shielded), and can use the Sense Motive skill as a free action.
- Pathfinder has a monster called a polong, an undead creature with an ability called Murderous Intent. This creates a seething aura of unrestrained violence and malicious intent that demoralizes anyone close enough to sense it.
- Street Fighter utilizes the Ki-based version as a major element known as the Satsui no Hadou (Surge of Murderous Intent). Akuma is considered a master of this energy and as such fights and kills anyone who faces him. Ryu also temporarily gets possessed by this energy as Evil Ryu, and tends to go further than Akuma. This is an especially present element in the Alpha series and the Ryu Final Manga. Oni is Akuma consumed beneath the Satsui no Hadou and turned into a monster that seeks only to kill and radiates his killing intent as a terrible aura around him.
- In the Nasuverse, skilled fighters can do this. In the Unlimited Blade Works route of Fate/stay night Shirou is able to sense that he is being followed by Archer because he is taunting Shirou with his killing intent. When Shirou calls him out on it he is impressed that such an unskilled magus could detect it. Shirou also uses Archer's killing intent to tell from where he is launching his attack against Berserker during their fight in the graveyard, and notes that it's directed at more than just Berserker.
- And then there's True Assassin's Presence Concealment skill, which renders him virtually impossible to find, unless he's preparing to attack a target in which case his own massive Killing Intent betrays him and makes he much easier to find. Though, in all fairness, when this time comes it generally is already too late.
- Angela from Princess Waltz is right there with with the likes of Kenpachi in terms of bloodlust. In many occasion her glare has caused hardened warriors to flinch and even think that they were vomiting blood after being Impaled with Extreme Prejudice just from being 'hit' by it.
- In Vampire Savior/Darkstalkers 3, B.B. Hood, a bloodthirsty Special S-Class Darkhunter, is so malevolent that her stare alone can instill a paralyzing fear into the lower-ranked Darkstalkers of Makai. This same darkness in her heart was what caught Jedah's attention and allowed her to enter his Majigen. Let it be said that B.B. Hood is the Token Human of the cast.
- In Super Smash Bros., while chatting with Otacon, Snake mentions Ganondorf is "giving off a murderous vibe." He's also uneasy with trying to fight him - "even getting close to him makes my skin crawl."
- The Pokémon game franchise has the attack Dark Pulse, introduced in the fourth generation. It's described as "a horrible aura imbued with dark thoughts", and may cause enemies to flinch.
- In Higurashi: When They Cry, Keiichi refers to being able to feel (or not feel) "murderous intent" and sometimes uses that to decide if someone is trustworthy.
- Killing intent is actually the entire reason your attacks damage monsters at all, as monsters are weak to strong negative emotions (being made of magic and all). As a result, bosses in a No Mercy run tend to be One Hit Killed. Conversely, in a Pacifist Run, when Undyne challenges you to a rematch during her "date", you'll deal only 1 damage whether you use the "Fake Hit" command or Fight her for real, because to even get to this point you have to go out of your way to never kill anyone.
- Monsters seem able to pick up on your killing intent pretty easily; despite the lack of any physical changes neutral monsters will treat a pacifist Player Character very different from one who's killing regularly or especially on a No Mercy run.
- Early in The Dragon Doctors, the invisible Murder, Inc. assault is detected in advance due to so many people radiating killing intent at the same time.
- One Nerf NOW!! arc featured a RED Engineer on a Tranquil Rampage Of Revenge after his Sentry Gun is destroyed. A BLU Heavy-Medic pair confront him, but are intimidated by his obvious rage. They think better of fighting him, and as a result they manage to survive their encounter with him, where BLU Scout, Sniper, Demo, and Soldier did not.
- The Gamer: Played for Laughs. Jee-Han gains the ability to sense killing intent, which manifests (like all his other powers) with a system popup. He most often gets these popups when he's hanging out with a girl, and one of the other girls sees them together.
- As mentioned above, Killing Intent can occur in everyday life, to an extent; i.e. body language, verbal cues, and the way you can just FEEL it when someone is glaring at you.
- Ever been walking along and all of a sudden you feel the hair on the back of your neck start to stand, or you feel a twinge in your gut, you look around and realize that a person or an animal is staring at you? You may not see, hear, or smell anything consciously, but your subconscious mind still picks up on these cues and reacts to them.