Adorkable: Li. Very, very much. He's so adorably inept, clumsy, kindhearted, and naive that you just want to hug him, and nobody would ever suspect he's secretly the Black Reaper.
Amicable Exes: Only apparent in the last time he's with Amber. After being hell bent on killing her for most of Season 1, he finally gets to hear her side of the situation and makes peace with her in a very touching Cool Down Hug.
Anti-Hero: A hitman for The Syndicate who doesn't really bother to question the morality (or, more often, lack thereof) of his assignments, with no compunctions about cheating, killing, or torture if he feels it's necessary.
Big Brother Instinct: Towards the aforementioned little sister in the past, and, depending on whether you're wearing Shipping Goggles or not, Yin. Toward the end of the second season, he also starts to treat Suou this way.
Big Eater: He's both an excellent cook, and known for eating a ridiculous number of servings per meal. Granted, he probably burns a lot of calories due to all the super powered contractor fights he partakes in, but still. Since he's a Contractor, it initially seems that his eating habits are his Remuneration, but it turns out that, nope, he just really likes food.
Chiaki: You are going to get so fat. Sure, maybe you can get away with it now, but once you hit thirty and your metabolism slows down— well, if there's any justice in the world...
Bishōnen: First manga only. The art is much more stylized than either anime series or the second manga, making him look pretty instead of handsome.
Dark and Troubled Past: Extremely. Start with dead little sister and betrayal by his girlfriend and work up from there: his little sister became a Contractor and was recruited by The Syndicate, and he joined as a Badass Normal to try to protect her. They were both in their early teens. After a few years of very mixed feelings, guilt, and trauma later, his then-girlfriend Amber (apparently) betrayed him, and his sister disappeared when Heaven's Gate exploded. He basically woke up with her powers, no sign of her, and no clue what the hell happened.
Permanently. Because his eyes are black, you can count on one hand the number of times you can tell the pupils from the irises, and they get stylized to dark blue-gray. We never once see light reflecting off them.
Quite a few contractors display this in the series, to signify how they aren't happy, or anything else regarding emotions for that matter. Which makes the revelation that Hei isn't properly a Contractor and doesn't have their sociopathy all the more horrible, because he was already like that before he got powers.
Expressive Mask: Very subtly. While his mask's mouth is usually angled upwards in a grin, during serious scenes it's angled downwards (with a little help from the camera) into a much more somber/neutral expression.
Face Palm of Doom: All the time; it seems to be his preferred method of frying someone.
The Gadfly: Hei does have a sense of humor, though you rarely see it. It usually takes the form of playing jokes at at the expense of someone else, such as in episode 3 when Mao got caught by Li's landlady. She contemplated selling Mao to a meat market, which Li seemed to disagree with before adding "...Though [cat meat] might be tasty." Mao was not amused.
Good Eyes, Evil Eyes: Watching Hei's eyes in an episode where he's mostly being Li is highly entertaining, just to see if you can spot the moments where his personality switches. In general, as Li, they're either closed or very wide, and narrower the rest of the time.
Grappling-Hook Pistol: Or rather, retractable cables with snap-hooks. Though twice, when he's had to get a cable particularly far away, he used a crossbow.
Half-Human Hybrid: He's not quite a Contractor- he has his sister's powers, but normal emotions and no remuneration.
Heroic Neutral: He'd really prefer to just be left alone, but the Syndicate isn't about to let someone so useful get away from them. Consequently, although he usually just does what he's told, he's still the group's loose cannon and will occasionally ignore orders entirely.
Immune to Bullets: Thanks to his coat. Subverted when Huang shoots him in the leg when he isn't wearing it and he spends the rest of the episode limping.
Important Haircut: Once he arrives back in Tokyo in the second season, he does this to illustrate his return to his former self.
Irisless Eye Mask Of Mystery: His mask seemingly has no eyeholes and just have eyes and mouth seemingly painted on it, making it perfect for concealing his Secret Identity and adding to his "Black Grim Reaper" persona's mystery.
Offscreen Teleportation: Once, he managed to disappear from about ten feet in front of Kirihara in the time it took her to put on her glasses, while she was pointing a gun at him and he had a bullet wound in his leg that had him limping badly. And there wasn't anything tall enough to do a Building Swing escape in the area, so that possibility is out.
Out of Character: In universe, Hei does not behave like a typical contractor. They're supposed to be emotionless, pragmatic, and incapable of empathizing with others. Hei does have emotions, has a kind side, and is known to act on these feelings without much rationality. This puzzles both ally and foe alike.
Paper-Thin Disguise: Played with. When he's on a job, he wears a white mask and a bullet resistant black overcoat. However, it's less of a disguise, more of means to keep witnesses from getting too close a look at him. It works because he moves too fast for anyone to get more than a glimpse of The Black Reaper.
Reality Warper: Shock and Awe is only one manifestation of a more general quantum-manipulation ability that Dr. Schrader mentioned could even be used for Super Empowering. When he's in the Gate, he can basically restructure everything around him.
Shock and Awe: Hei can't shoot lightning, he can merely give off electric discharges, meaning he has to conduct the electricity to the enemy. Enter the metallic choke-wire. But he used that even before he could zap people.
Soul Fragment: The source of his powers is what's left of his sister's mind after Heaven's Gate fused them.
Static Stun Gun: He uses his electricity power like this at times. In one case he actually pretended to have a taser, because he wasn't disguised at the time.
The Stoic: Borderline Stoic Woobie; remember his traumatic personal history and that he never wanted to be involved in any of this and the only reason he's working for the Syndicate is that they'd kill him if he tried to leave, and the reason he pretends to be a vicious, emotionless killer becomes a good deal clearer.
Superpower Lottery: A low-key win at first glance; he's got a pretty powerful attack that can also be scaled back for nonlethal takedowns, and doesn't have to go line up pebbles or anything similarly inconvenient every time he uses it. However, it turns out he really hit the jackpot— his powers are from his sister, so he's got no remuneration, and under the right circumstances he's an honest-to-god Reality Warper.
The Worf Effect: The interquels and second season feature quite a few instances of this, though it makes some sense when you consider that he had the element of surprise in almost every fight he got into in the original series.
Yin/Izanaminote In the OVA episodes and Darker Than Black: Gemini of the Meteor
Apocalypse Maiden: In the fourth OVA and second season, it is implied being in the Gate at the end of the first season has made Yin capable of killing every human and Contractor on the planet, as discussed in the OVAs.
Blind Seer: It's not obvious that she's blind until a flashback from before the appearance of the Gates, since her abilities pretty much perfectly compensate for it.
Brown Note: In Season Two, she triggers Contractors to commit suicide.
Not Herself: At one point in the Gaiden OVAs, she speaks up out of the blue and starts coldly analyzing the problems with Hei's plan, then suggests another idea. He's rather creeped out, and it only gets worse a minute later when she says she doesn't remember saying anything.
Not So Stoic: She starts crying in one episode and occasionally shows evidence of a crush on Hei.
Tragic Monster: In the second season, simply by being alive Yin could end the world. She seems aware of it as despite the world's governments and the Syndicate trying to control her and prevent the end of the world, Yin wants Hei to kill her.
The Unsmile: She uses her fingers. However, unlike most examples of the trope, it's cute rather than disturbing.
Even Evil Has Standards: He may be really bigoted against contractors, but he couldn't bring himself to shoot Yin/Kirsi, when she started to cry, which a doll normally can't. He also wouldn't hand her to a syndicate member later to be "reset".
Mundane Fantastic: Very few of the people he interacts with are particularly surprised by a Talking Animal. However, this is probably just due to exposure, since several characters are very surprised when he starts talking.
The Deuteragonist of Season 2, a half-Japanese, half-Russian schoolgirl. Her father is a scientist studying ME and her brother is a Contractor; her mother is a photographer who moved to Japan eight years ago. She gets pulled into the plot because of attempts to capture her twin and winds up hanging around Hei. In the third episode, she develops the Contractor ability to summon an anti-tank rifle and wield it easily despite its size.
Half-Human Hybrid: Like Hei, she has Contractor powers while retaining human emotions/morals. Unlike him though, she does have a Remuneration and temporarily loses those emotions/morals when her powers activate.
Superpowered Evil Side: When being driven to the brink, her necklace becomes a BFG and she becomes a merciless Contractor, albeit one who wants to kill other Contractors for their evil actions. After this first time though, she retains her morality when using her powers.
The head of the TMPD's PSB Foreign Affair Division, Section 4, which covertly deals with contractor-related crimes and terrorism; she takes a special interest in the cases related to BK-201, which starts to grow into an obsession over time.
Dating Catwoman: Her relationship with "Li"- given the morality of the series, it's hard to tell which of them is the "Catwoman."
Fair Cop: In season 1 and part of season 2 until she quits the police force.
Fatal Attraction: She falls for Hei even though she connects him to BK-201 as early as episode 18. It takes a couple suspicious coincidences, a partially-cracked mask, "Li" slipping into his Black Reaper voice, an accidental Meaningful Echo, and some surprising openness on his part before she figures it out/admits it to herself.
Genre Savvy: Part of the reason she's obsessed with Hei. She's figured out that he's going to be at the center of any world changing event that happens in the future.
Go-Go Enslavement: Alice insists on dressing her in a qipao as punishment for forgetting about her party.
Hazy Feel Turn: From the Tokyo Metropolitan Police Department Public Security Bureau to Ministry of Internal Affairs and Communications then to the New Syndicate
Nepotism: Her father is ranked above her on the police force. She doesn't appreciate his attempts to ensure the correct progression of her career. In the second season, she quits her job out of frustration and a wish to find Hei.
Stalker with a Crush: She's still trying to find Hei in the second season, even though she's no longer working for the police department. And by "trying to find" I mean "obsessively watching the star BK-201 through a telescope." Kanami informs her that she needs to get over him and find another guy.
A member of Section 4 and closet Big Name Fan. She is an official liaison officer to the National Observatory to check on contractor-related appearances in Japan.
Bunny-Ears Lawyer: Likes to read and write erotic fanfiction and can be kind of ditzy, but also shows some competence, figuring out BK-201's identity when the rest of the police force failed miserably.
Stalker with a Crush: She stalks Hei for a few days, leading the group to suspect that she's working for someone to try to interfere with their mission.
Too Dumb to Fool: Not dumb exactly, but like the other Wrong Genre Savvy characters, she makes some accurate deductions, despite having odd logic and sometimes the wrong conclusion- she figures out that "Li" is the Black Reaper on account of his "sexy collarbone"
Second Face Smoke: In his introductory scene, he's dealing with some gangsters and voices his extreme disapproval of smoking early on. When they try to double cross him, one of them lights up and contemptuously blows smoke in his face. Big mistake.
Shout-Out: He is a secret agent. He is an only guy whose name is a month and a date - a certain guy's birthday.
Smoking Is Cool: Sometimes subverted, sometimes played straight; the first time we see him dealing with his remuneration, he starts hacking out the smoke in a decidedly un-cool way, but the rest of the time he makes it look good.
Faux Action Girl: In the episode where she's injured, Huang shows Hei a sheet of paper listing her kills which are numerous, but in-series, she just assists November 11 and schleps July around. Although she does manage to score a kill on the enemy contractor Goran. Not to mention nearly killing Hei ... until he kills her of course.
Heart Is an Awesome Power: Her abilities are deadly in combination with November. In the sequel series, she show that she can summon a swirl of water around her opponent's head to drown him on his feet.
Making a Splash: The second season shows that her powers extend at least a little beyond rainstorms.
This Looks Like a Job for Aquaman: The conditions for her only solo kill are rather contrived, though her following showing against Hei is still relatively impressive.
You Gotta Have Blue Hair: Weirdly, she is introduced with black hair in the second season, which makes you think that her hair might have been dyed. Nope- the black hair is a wig covering her apparently naturally blue hair.
A Contractor introduced in Season 2. He is part of the same team as April and July.
Achilles' Heel: He can pretty much do anything as long as he is looking at you and you at him, but Hei throws his longcoat over August's head and electrocutes him while he is powerless.
Blessed with Suck: He's a former stage magician and received the power to do real magic, something which would make him the greatest magician ever. Unfortunately, his Remuneration is to give away how magic tricks work, something which hurts his pride as a former magician and takes away any professional benefit he could get from his powers.
The founder of Evening Primrose, who used to work for The Syndicate, the CIA, and MI6, but betrayed all of them. She was in South America during Heaven's War, and Hei considers her responsible for what happened at its end.
Femme Fatale: Just ask Hei. ... although he'd give you the wrong answer. Hei thinks she is, since she betrayed his group in Heaven's War. However, his sister was in on it too, and they didn't tell him because they both knew that continuing to work for The Syndicate was safer for him in the long run. She still loves him and wants him to be happy.
I Want My Beloved to Be Happy: She moved heaven and earth just to get into a position where she believed Hei could be happy by turning Japan into his own cosmic plaything at the cost of all Japanese humans.
Meaningful Name: The mineral amber led to the discovery of electricity; see the entry on the main page for details.
Necessarily Evil: Seen in how even in her "kill all Japanese humans" plan, she was willing to use the last of her power and seemingly Ret Gone herself.
Not So Stoic: Breaks her jolly demeanour when Hei is facing a dilema on whether to let the Contractors or humans die, she's angrily asking if saving contractors is what he wanted in the first place. As this is one of the only times she's not smiling, it's rather jarring.
Disney Death: Seemingly burnt to death along with Brita at the end of the first season, he shows up in the third Gaiden, but now is bald with some signs of scarring, and has an Eyepatch of Power over his "shut" eye.
Kick the Son of a Bitch: Runs around blowing up buildings, hints that he intends to do more, attacks Hei because he's jealous and runs November 11 through a gauntlet for no real reason when his time would be better spent escaping. Not even Amber is sad when he dies.
Naked on Arrival: Her teleportation can't carry anything non-living, so this applies to anyone she teleports, including herself. Oddly enough, she does retain her purple lipstick through the teleportation.
Punchclock Villain: The only reason she's involved with The Syndicate at all is so she can work at the Gate, and her contact with Hei is apparently the only time she's actually had to do anything for them.
Evil Counterpart: He even has the same powers as Hei (the main difference is Hei's powers are straight Reality Warping that he uses almost exclusively for electricity, while Nick's are actually electricity)
Part of the team dedicated to hunting down Hei and Suou, a contractor with the ability to turn solid objects into heavy armor. Has a habit of hitting on everyone he encounters.
Bait the Dog: Genma initially comes across as an affable, jokey Lovable Sex Maniac, and a pushover at that, since Suo "defeats" him by throwing a trash can over his head. Further appearances establish him as a sociopathic pedophile who finds wanton brutality incredibly amusing.
Depraved Bisexual / Anything That Moves / general pedophilia: Genma makes so many sexual references that it's not quite clear what "direction" in which he swings or even if he's restricted himself to a "direction". Still, he seems to attracted to children.
Suspiciously Similar Substitute: Narratively, his role is very close to November 11's: they're both Contractors who end up working closely across organizational lines with Kirihara, despite her mistrust of Contractors in general. What's more, Genma and November 11 both cultivate relaxed, wryly humorous demeanors to obscure how dangerous they really are. And they both love doing the Anti-Villain boogie early on in their respective seasons. But whereas November 11 ultimately comes down on the side of integrity and fortitude, Genma lands in a much uglier moral space. The former is Affably Evil, while the latter is most certainly Faux Affably Evil.
Does Not Like Men: Unfortunately for her, her Remuneration is to French kiss them. She tries to get "rid of the taste" by rinsing her mouth with vodka and kissing a women right afterwards, not giving a rat's ass about the women in question wanting it or not.
Even Bad Women Love Their Mamas: Despite being shunned by her family, being informed that her mother is dying distracts her during a fight with Hei, and she muses about still having some caring towards her mother.
Evil Counterpart: Has similar dress sense, weaponry, and personality to Hei; her background as The Ojou who broke from her powerful family is rather similar to that of Kirihara.
Bait the Dog: Initially appears very moe as well as friendly and outgoing, but she follows in the footsteps of the similarly affable Dr. Shrader in having For Science! as a mantra, pursuing "experiments" without concern for human life.
Blood Knight:This trait of his eventually becomes a DeconstructedTrope as it causes his death. Although he figures out Amber would only let him fight Hei if she knew Wei would lose and die and saw this via time travel, he still wants to fight Hei to the death due to a mix of pride and enjoyment.
Good Scars, Evil Scars: Evil ones- his arms are covered with scars due to him cutting himself to use his powers/pay his Renumeration, and after Hei electrocutes him, half of his face and body is burned.
Too Dumb to Fool: The only person to notice that that one Chinese exchange student keeps showing up in weird situations. However, he quickly decides that it's probably a coincidence and he's being paranoid.
Quite possibly the most dangerous contractor in existence, she killed hundreds or even thousands in South America- and then something happened that removed her powers and some of her memories but restored her emotions to normal. Now she's wracked with guilt over what she did, leaving her as probably the only case of a woobie who ate babies in history.
Two Contractors working for FSB to capture Yin. Bertha's power allows her to force objects to resonate, usually breaking them, although it can also stop someone's heart; Itzhak can absorb observation ghosts and use them to manipulate and control the minds of dolls.
Alas, Poor Villain: Their deaths are most definitely played for sympathy. It helps that they feature as the villains of what's already probably the most heart-wrenching story in the series.
Bertha's backstory (get the Kleenex ready, it's a very, very sad story): She was a opera singer and heavy smoker. She gave up smoking for the time of her pregnancy and some months after. Afterwards she started to smoke again worse then a chimney, her daughter, who she described as angelic, found the cigarette butts, swallowed some of them, they got stuck in her throat and she choked to death on them. After that, her mother was, understandably, extremely depressed, but a month after this tragic event, the stuff with the "Gates" happened and she became a contractor. It was hinted, that it was a relief, since a contractor has no or very limited emotions and probably this negated her depression somehow.
Blessed with Suck: Bertha has to swallow and puke up stuff (she chooses cigarettes) as her renumeration/obeisance (she can theoretically swallow and regurgitate any object she'd choose, but she does that with cigarettes as to remember her daughter, who chocked to death on her mom's cigarette butts she swallowed).
Pillar of Light: A side-effect of Itzhak's power; when he dies, all the observation ghosts he's grabbed disperse at once, creating a huge version.
Warrior Poet: Literally, in Itzhak's case: his remuneration is writing poetry.
What Kind of Lame Power Is Heart, Anyway?: Itzhak has one of the most specialized and useless-in-combat abilities we've seen, which is presumably why he was paired with someone who can kill quietly and almost instantaneously or cause massive structural damage.
Wicked Cultured: Both, in different ways, between opera singer Bertha and reluctant poet Itzhak.
The primary antagonist of the Interquel manga, Shikkoku no Hana. His power is to dissolve matter, and this ability to manipulate the connections between atoms allows him to give normal humans Contractor abilities.
Nigh-Invulnerability: Since he can break down pretty much anything, bullets are completely useless and even attempts to gas him just result in him chemically decomposing the gas. The cops manage to hit him with tranquilizer darts and electricity.
A young schoolgirl Hei encounters in Shikkoku no Hana. After being seduced and betrayed by her coach, Daisuke Mioka, she desires to become a Contractor in order to exact revenge. And then she meets Harvest...
Heel Face Door Slam: She's not dead (yet?) but she would be marginally okay if she had spared her teacher. Of course, she WOULD'VE spared him (at Hei's urging, of course) if he had decided to not be a dick at that very moment.
Interrupted Cooldown Hug: A non-hug version: Hei has pretty much managed to talk her down from her Roaring Rampage of Revenge, when her coach comes up behind her with a taser and knocks her unconscious. Retribution was not long in coming, from both Hei and Azusa.
Shoot the Shaggy Dog: Hei puts a lot of effort into trying to convince her to stop her rampage before the flower blooms and she's completely screwed. She decides to finish it at the last minute anyway, though he kinda deserved it.
Too Dumb to Live: Really, Daisuke? You're going to taser someone that you know would love NOTHING more than to kill you in the most horrible way possible, right when they decide to spare your life? Really?
And even if she hadn't killed him for that, Hei certainly would have.
A contractor of one of PANDORA's many factions working to kill Harvest. Her power is teleportation through use of black portals. Her Doll is a modified cyborg named "Champ."
Suo's brother, who was transformed into a Contractor. His power is to produce copies of things and people with one trait changed, and his remuneration paralyzes his legs, putting him in a wheelchair most of the time.
A Russian FSB Contractor featuring in the second series.
Ax-Crazy: Played with: While most Contractors can kill without much thought, becoming a Contractor actually made him less kill-crazy. Also, theoretically, he now kills in the most painless way possible. But, yes, he's still crazy.
Deadly Gaze: His powers allow him to shut down his victims' brains by making eye contact. The effect is degenerative but not instantaneous, making his victims die slowly as their cognitive and motor functions gradually shut down.
A Contractor who features as a major antagonist in the interquel OVAs.
The Bad Guy Wins: Despite being shot and nearly bleeding out, he still manages to slaughter many Contractors that wanted to live in peace and forces Yin into awakening Izanami, creating a worldwide threat that could kill many humans and Contractors and setting up the second season. He still ends up dying due to Izanami, although it is less of a Karmic Death since he seemed to enjoy being killed by Izanami as he knew he had already won.
Fantastic Racism: Reveals he doesn't like humans to intelligence agencies paying him a ton of money for Yin/Izanami...Shichi tosses their money away and manipulates the situation so everyone there will die. Though he didn't see himself dying, probably, but didn't care because he won in the end of the OVA.
The Social Darwinist: Due to being exploited by humans, he began to wonder why Contractors don't exploit humans...after all Contractors have powers and humans don't.
The Sociopath: Seems to have no attachment to others, even killing his partner who he seemed to be friendly with and had no problem killing a lot of Contractors, despite his claims that Contractors are better than humanity and his dream of them ruling humans. Whereas other Contractors have felt some emotion towards others, Shichi's emotions can be summed up as spite against humans.