Ax-Crazy: His Kerberos spine gives him killing urges that are extremely difficult to resist, but even without them, his past has left him so fucked up that he's one annoyance away from going on a rampage, at least before he manages to calm down over the course of the story.
Berserk Button: Heine really doesn't like it when people try to hurt Nill. He also really doesn't like it when women touch him, though he's ok with it if it's Nill, and later, if it's Naoto. And if, for some reason, you find yourself holding one of Heine's guns, don't fire it.
Chain Pain: Heine likes to tangle mooks up in the chain connected to the grip of his Mauser C96.
Character Development: Over the course of the story, he learns to open up about his past and put his trust in others more. He even becomes a mostly-decent human being, and he no longer goes apeshit when women touch him, especially if the woman in question is Nill or Naoto.
Child Soldier: What he was bred to be. While he escaped before he actually began to fit the trope, he still took home some horrible mental trauma.
Cool Guns: This guy uses two awesome guns: a white Mauser C96 connected to his belt by a nifty chain, and a black P08, or as it's better known, Luger.
Dark and Troubled Past: Long story short, he was created in a lab and then physically and psychologically tortured before being forced to kill his friends.
Designer Babies: He and all the other Kerberos spines are test-tube babies.
Dissonant Serenity: Unless someone presses his Berserk Button, he's disturbingly calm whilst other people are getting killed. In fact, combat with anyone unrelated to his past is one of the few times when he seems genuinely at peace.
Heroic Neutral: He mostly wants to be left alone. He leaves this trope behind when Einstürzen's organization becomes more central to the plot, as he has personal beef with them.
Heroic RROD: Yes, you read that correctly. In chapter 72, thanks to Naoto, whom Einstürzen briefly takes control of, Heine ends up with a stab wound straight through his gut since Naoto's sword is specially made of a material meant for dealing with Cerberus spines.
He's also quite nice to Naoto, and he even tries to cheer her up after her second Heroic BSOD. The fact that at one point, he reached out to her to try to bring her back from being possessed by Einstürzen, and even resists the influence of his spine when it tries to force him to kill her, says a lot about how much he cares for her.
Unscrupulous Hero: In any other setting he would be more of a Pragmatic Hero, but the setting of Dogs is utterly shitty and for some reason, a lot of people feel the need to provoke him into carrying out the murderous urges his spine gives him.
Big Brother Instinct: Towards his brother Dave's fiancee, Daniella. She lost it after Dave disappeared and messing with her is something Badou will not stand for. In fact, when he and Beltheim had each other in a Mexican Standoff, he listened to everything the latter said in silent anger, but the moment Beltheim brought up Daniella, Badou pulled the trigger.
Big Damn Heroes: Pulling the possessed Naoto off of Heine and removing her sword before it could make it to his spinal cord in 72.
Butt Monkey: Honestly, nobody gives Badou a break, not even the universe in general.
Crouching Moron, Hidden Badass: Badou is a textbook example of this trope. He's an idiot, he's a coward, he'd rather run like hell away from you than actually stand up to you... until you take his cigarettes away. At that point the MAC-10s come out and your best course of action is to get the hell out of range, and fast.
Knight in Sour Armor: The guy is operating under no delusions about how cruel and unforgiving the world is, and he's not above doing illegal jobs to put food on the table, but he puts his foot down when illegal becomes immoral. In fact, the first chapter of Bullets and Carnage has him and Heine taking down a child-slavery/prostitution ring, knowing that it probably won't accomplish much, but doing it anyway because it's the right thing to do.
Must Have Nicotine: He's generally a somewhat useless and good-humoured one-eyed chain-smoking PI with bad luck, but when deprived of a smoke for about three minutes at a time he goes Ax-Crazy and becomes completely unstoppable in search of a smoke/punishing the reason he doesn't have a smoke. Several antagonists deny his last request for a puff and never do anything ever again. He takes this problem of his in stride. So do all his friends, except when he trashes their bar. It seems to be viewed in-universe as a sort of (kind of stupid) special ability, and is played for drama and comedy at the same time.
Scars Are Forever: Badou has scars on both his right hand and right eye (underneath the eyepatch). These are implied to have something to do with his older brother, but little more than a very brief, bloody flashback has been shown so far to explain the wounds.
Unfriendly Fire: He's on the recieving end of this, courtesy of Mihai's gun and Beltheim's mind control.
Weapon of Choice: Subverted. At first it seems like he prefers Ingram Mac-10s, but it really was just coincidence that he always ended up with them, and he actually prefers a single Glock. In fact, the second time he picks up a Mac-10, he even asks why he has to use them:
Badou: "And what... do you expect me to do with these? Again with the Ingrams?"
Would Not Hurt A Child: Downplayed, given how he was up against Luki and Noki. He lured Noki in front of a massive blade which shot forward and cut her arm off, despite knowing that there was a good chance it would have killed her. However, he refused to just abandon her unconscious body and carried it with him, even when the extra weight slowed him down when he really needed to stay quick on his feet.
Tragic Keepsake: She keeps Fuyumine's sword, but that doesn't really count as much because she actually inherited it from Magato and she mainly hangs onto it so she can use it to kill Frühling. What really fits is Fuyumine's coat. Even though it's been years since his death, and even though it doesn't really fit right, she still wears it all the time.
X Marks the Hero: She has a massive X-shaped scar on her chest, and like Badou, she's one of the more heroic characters in the series.
You Killed My Parents: The reason she trained with Fuyumine was to one day kill him. Subverted when he is killed by someone else and it turns out he was innocent anyway. She is now looking for their true killer.
The fact that he lived long enough to stop being bishonen should tell you how hardcore this guy is.
A retired assassin and occasional errand runner for the owner of Buon Viaggio. He gets lost. Often.
Badass Bystander: He's just an old man, nobody cares about him, nobody's out to get him (at least at first). He still finds himself involved in the series' major conflict because he has the bad luck of always being close to trouble when it happens, and his sense of right and wrong forces him to step in.
Badass Normal: He has no Kerberos spine, only a lifetime of combat.
Baguette Beatdown: He weaponizes the restaurant bread at one point. It's about as hilarious as you think it is.
Big Brother Mentor: To Ian, though they both saw each other more as father and son. He also seems to be becoming one of sorts to Badou as well.
My Greatest Failure: Is very bothered by the fact that he was unable to stop his student from murdering the woman he loved. He's even MORE bothered by the fact that his student even turned out that way.
Second Love: More than ten years after the death of his lover Milena, he got involved with her best friend Kiri. It's always possible that they are merely Platonic Life Partners, but the story drops a lot of hints otherwise.
Unfazed Everyman/Badass Normal: She's somewhere between the two. She knows how to use a gun, and even saved Mihai's life at some point. She is completely unfazed by gunfights breaking out in her restaurant.
It's sad that she's one of the few people in this series who spends most of her time smiling.
Can't Spit It Out: This happens to her a lot when it comes to Badou, the most prominent example being after the attack by Einstürzen's Dogs: she bitched at him for putting her in danger and threw him into a headlock, but she really just wanted to tell him how worried she was about him. Couldn't do it, though.
Childhood Friends: With Badou. She apparently knew Badou's brother quite well, which means she was friends with the two of them for quite some time before Dave's disappearance.
Big Brother Mentor: A downplayed example for Badou and Mimi. He doesn't see them all that often, but he looks out for and advises them and it's clear both of them look up to him.
Big Damn Heroes: Just as Mimi is about to be killed by Magato (and possibly raped first), Doug and a few of his men, who were passing by for whatever reason, interrupt and stop him.
Cool Old Guy: The only reason he isn't as cool as Mihai is because he isn't an uber-badass ex-hitman. He's a great guy and he seems to be a Big Brother Mentor for Badou and Mimi, and a rarity in mangas like this: an honest cop. In fact, when Einstürzen's men attack the Underground, he doesn't hesitate to mobilize his men and head out to evacuate as many civilians as possible.
Da Chief: He fits both of the subtypes detailed on the trope page: On the one hand, he's quite lax when it comes to regulations and gives his men a lot of freedom because he knows that most of them will do their jobs responsibly. However, when the shit hits the fan, such as when Einstürzen's mooks attacked the Underground, he smartens up and enforces discipline in his men.
A Father to His Men: He looks out for the cops under his care, and given his experience, he acts as a mentor to the younger ones.
Friend on the Force: Because of this guy, the most trouble Badou gets from the cops is one or two complaints about how much paperwork his antics cause.
Good Is Not Dumb: Doug is one of the most unambiguously good characters in the series, and he has the authority to actually do something. Magato even comments that the cops have been giving him a hard time.
Intergenerational Friendship: With Badou and Mimi — Badou's somewhere in his early twenties, Mimi is the same age or a little younger, and Doug is at least in his fourties if his appearance is anything to go by. He's also on good terms with Luki and Noki, who are younger than Nill.
Knight In Sour Armour: He's so world-weary that not even child-bounty hunters surprise him, but that doesn't stop him from doing the right thing or taking his duties as a police officer seriously, even when it would do wonders for his life expectancy to just walk away.
Luckily My Shield Will Protect Me: He and his men make good use of solid metal riot shields when fighting Einstürzen's goons. They were thick enough to deflect gunfire, though a few cops got shot when they got flanked and shot at from the side.
Luminescent Blush: He gets one when Badou reminds him of how he would always check up on Dave's fiancee.
Nice Guy: He's probably tied with Nill as the most unambiguously nice character in the series. The only time he even gets angry and raises his voice is to shout at his men to focus while they're in the middle of a firefight. It's later revealed that he's continued to look out for Dave Nails' fiancee, and despite it being heavily implied that he has a crush on her, he never once made a move on his friend's woman.
Reasonable Authority Figure: He doesn't do anything about Badou's antics because he knows Badou would never be dumb enough to kill anyone and would take responsibility for things like property damage.
Yandere: She showers those who do well against her creations with affection, though she's rather callous to those who don't but still have the nerve to survive.
Heine's brother.REALLY loves messing with his head.
Arch-Enemy: Subverted. At first it looks like Heine really hates Giovanni, but his animosity to his brother only really lasts as long as Giovanni stands in his way. In fact, after putting a bullet through Giovanni's skull, Heine looks almost melancholic as he whispers, "There... now you can sleep for good, Giovanni."
Power at a Price: Giovanni can regenerate from headshots, something that Heine can't do. However, it's revealed that it was because he was given an "upgrade" that allows him to regenerate from extensive brain damage at the cost of his memories. In other words, he's been given an immortal body only to die mentally.
Absurdly Sharp Blade: Luki's first swords can cut through almost anything because there's just so much weight behind them. The claws she gets later are just plain sharp, however.
Achilles' Heel: Their cybernetic arms are powerful and more than capable of handling the massive weight (and recoil, in Noki's case) of their weapons, but they're not very well armoured, and unlike the rest of their bodies, they won't regenerate.
Ambiguous Innocence: The twins are probably the most innocent little children you could ever find in this series. They're so innocent, in fact, that they don't know killing is wrong, so they have no problems with it.
Gatling Good: When she and her sister reappear in Chapter 82, she's switched out her BFGs for a smaller but much cooler gatling cannon, complete with a back-mounted ammunition drum and everything.
Artificial Limbs: They were born conjoined at the shoulder, and so both of them only have one real arm. The ones they're missing have been replaced by powerful weapon mounts.
Ax-Crazy: They don't know that killing is wrong and treat it like some sort of game. They understand the what killing is and what it means if someone dies, and they don't want to kill any of the people they like, but the fact remains that if they see a reason to kill someone (a reason which can be and often is "He had a weapon, so he was looking for some fun.") they'll do it.
Badass Adorable: While neither of them is any match for heine alone, when fighting together, they're close to unstoppable.
Bottomless Magazines: Played straight with Noki's first two guns. The second had a small triangular ammo-belt container resembling the cloth containers often seen on M60s and M249s, but it still fired off a lot of lead and she's never seen reloading. Her first gun didn't even have a magazine, though it's possible all that bulk was actually some sort of internal magazine. It's averted with her third gun, which is clearly fed from a backpack mounted ammunition drum.
Bounty Hunters: They do this in their off time when Einstürzen doesn't have anything for them to do, and they mostly do it for pocket money so they can buy food from Kiri's restaurant. Though some of the newer and less experienced cops are shocked, the older veterans just take it in stride, because they're good at what they do, they bring in live criminals too terrified to resist, and child-bounty huntersaren't uncommon in this setting. They're even friends with the Police Chief.
Creepy Children: The cheerful way they attack people has shades of this trope, but they don't really fit until they're re-brainwashed by Einstürzen.
Creepy Twins: Downplayed. Their fondness for each other and the extent to which they're in sync with each other can get quite unnerving at times, but they're generally too genuinely cheerful to be all that creepy, and they're usually more adorable than anything.
Designer Babies: Perhaps unsurprisingly, they're not just twins but rather part of what can only be described as a litter of children. Knowing Einstürzen's track record, though, it would be safe to say they're the only ones left.
Dissonant Laughter: They genuinely love shooting/stabbing things, and like all children doing what they love, they laugh in the cutest manner possible while doing it.
Establishing Character Moment: Their first appearance in Bullets & Carnage has them outrun a speeding car and then land directly in front of it while engaging in playful banter, before they pull out massive weapons and tear the car apart. This immediately tells you what they're like and how dangerous they are.
Fake Arm Disarm: They've had their artificial limbs torn off twice. It's justified, however, in that their arms actually aren't very durable, and unlike the rest of their bodies, they don't regenerate or repair themselves. The fact that these arms and the weapons they carry are massive only makes them a bigger target.
Knife Nut: In addition to the BFS's installed, Luki's arm can also shoot out knives.
Lightning Bruiser: They're quite strong and pack massive weapons, and thanks to their speed and small size, they're hard to hit. They're also just as immortal as Heine is, they they may cross into Fragile Speedster when it comes to getting shot in certain places, as Luki was knocked out after taking a blade through the heart.
OOC Is Serious Business: They're different in Chapter 82: instead of being their cheerful selves, they're calmer and much creepier. They don't greet Heine, they're not excited about getting to fight, and Luki finds herself utterly terrified by both Heine and Naoto.
Punch Clock Villain: As much as they enjoy violence, they'll only pull out their weapons when working jobs for Einstürzen or if they see a criminal with a bounty. Otherwise, they're just like normal kids, and Naoto even got used to them after they stayed at the church for only a short while.
A swordswoman who works for Einstürzen. She leads a troupe of helmeted, black-clad Nigh Invulnerable minions. Nuki and Loki's apparent guardian.Recently revealed to be the original Naoto & also the killer of Naoto Fuyumine's parents.
Absolute Cleavage: Her suit is pretty low cut and it gives us a good view of her cleavage.
Affably Evil: Rather polite and formal to Bishop, even leaving him her name. She also seems to be rather kind, if professional, towards Luki and Noki.
Affably Evil/Faux Affably Evil: It's really hard to tell where he falls between these two tropes. At first he appears to be a straight example of Faux Affably Evil as he's always polite in a clearly psychotic manner, even as he slaughters people. However, it isn't a put-on. It's genuine. He'll be genuinely polite— maybe even helpful— in that psychotic way of his, and he'll keep being polite and helpful up until he decides he wants to kill you.
Attempted Rape: In Stray Dogs Howling in The Night, when Naoto was still living with Fuyumine, Magato tried to rape her.
Later, in Bullets & Carnage, he corners Mimi. While nothing is actually said, the way he was holding her was pretty suggestive. Luckily, the cops arrived before he even got started.
Blood Knight: There's no benefit to him challenging Heine other than because he wants to.
Chekhov's Gunman: He appears in Stray Dogs Howling in The Night where he is badly wounded when fighting Naoto, and it's implied that there was a good chance the wound would kill him. It's not until midway through Volume 4 when he makes a reappearance.
Vague Age: Or perhaps, Younger Than They Look. In the prequel, Magato seems noticebly older than Naoto (early 20's vs mid teens) whereas in the series proper, he seems 5 years older at the most.
The reason for this is Magato, while still very much younger, is from Frühling's generation at the organization.
Wild Card: No one is sure who's side Magato is on. He seems a bit obsessed with killing Naoto but expresses something resembling fraternal concern when her fighting style becomes inexplicably more cutthroat. He also drops his fight with Heine over the suspicion that she's in danger. It's implied that the only thing Magato cares about in any intense manner is Naoto but for what reason, purpose or even if this is a good thing hasn't been explained yet.
Relative Button: He invokes this with Naoto after he killed her parents. As it turns out, he didn't; he just told her that so that it would give her the strength to keep living, if only to live long enough to kill him first.
Silent Scapegoat: To Naoto, because it gave her a reason to live. With the reveal that he was, and perhaps still is, in love with Frühling, he may have actually been trying to shift Naoto's hatred away from her.
Badou's older brother. Seven years ago, he was a freelance Intrepid Reporter who got too close to discovering Einstürzen's opperation and was killed for it by Beltheim, then little more than one of Einstürzen's puppets.
Intrepid Reporter: It got him killed when he got too close to uncovering Einstürzen's opperation.
The Lost Lenore: To his fiancee Daniela. His disappearance shattered her mind, and even though Badou says she's doing much better by the time she's introduced, she still has episodes where she flashes back to before Dave disappears, and even mistakes Badou for his brother.
Men Can't Keep House: He and his constant messes are the reason Badou would make such a good housewife.
Director Zöllner E. Neubauten
The Director of the Central Administration Office.
A Lighter Shade of Black: He was once affiliated with Einstürzen and apparently continues to conduct similar experiments if his army of werewolves is any indication. That being said, however, Einstürzen's soldiers were sent to just kill innocents indescriminately, and though it is likely that Neubauten sent his men to stop them for less than altruistic reasons, they still endeavoured to minimize civilian casualties. Only time will tell if this sticks.
The Reveal: He's both a former colleague of Einstürzen and another person with a Cerberus spine, specifically the original, the Führer, and is waaay stronger than Giovanni. He's also in league with Ernest.
Enemy Mine: With Calcerino. They're plotting to kill Heine.
Ungrateful Bastard: Heine fights far better than even Naoto to defend Liza's territory from Einstürzen's "dogs" (Naoto was much less effective than him for much of the fight because she couldn't bring herself to kill her enemies, letting them get back up), yet Dominico held Heine completely responsible and acted like he brought the dogs down on the people for his own amusement.
Jerkass Has a Point: He points out that horrible things tend to happen whenever Heine and Badou are around. And they do. He's wrong about them actually intentionally causing these horrible things, though.