The Heroine and protagonist of the series (although you could make a case for Chrono being that), Rosette is a young exorcist with the Magdalan Order. Her talent with a gun is only matched by her talent for destroying things and getting into trouble. Although she has a hot temper and a loud mouth, underneath it all she's a genuinely caring person that wants to live her life to the fullest.
Action Girl: Let's just say when this girl shows up in a fight, you'd BETTER FUCKING RUN. Although in the anime, she gets a Distress Ball at the end, it's for rather legitimate reasons in-story and she still counts as this through and through.
Back from the Dead: In the manga's final volume. Rosette dies in Chrono's arms, but is revealed to have her spirit still residing in the watch. The rest of the heroes manage to save her and bring her back to finish her fight with Aion.
Berserk Button: Don't toy with her regarding her brother, or if you're a demon, talk about killing a mortal. You will regret it.
Big Sister Instinct: Her goal is to save her little brother from Aion. She goes as far as to don't hesitate to attempt to chase after Aion when Joshua is taken, even though she's only twelve years old at the time. Chrono admits in the manga that the main reason he made the contract with her is that he knew she'd run off alone if he didn't.
Blithe Spirit: Rosette has a tendency to rush into people's lives and change them for the better. This is lampshaded at the end of the manga.
Cain and Abel: It turns out Joshua's very loyal to Aion and doesn't want to give up his horns...so Rosette and Joshua end up on opposite sides of a war as Rosette desperately tries to get through to him.
The Caretaker: Rosette was almost this for her younger brother. Joshua was desperate to keep her from having to devote her life to him, which was part of his motivation for going with Aion.
Cast from Lifespan: Chrono's powers draw from Rosette's lifespan. She says she probably won't live to 30. She doesn't even make it to 25.
Domestic Abuser: Some of Rosette's tsundere antics towards Chrono make her come across as this—at one point in the manga he's even show laying in his own blood after a beating. Always Played for Laughs.
Handicapped Badass: A generous estimate gives her life expectancy to be no greater than thirty, but god damn if she isn't going to spend those years being as Hot-Blooded as possible.
The Hero Dies: Given the nature of her contract with Chrono, it's a Foregone Conclusion that Rosette is going to die young. When, where and how it happens, however, is an unknown, which contributes to the tension of the story.
Hero Insurance: Rosette can be pretty destructive sometimes. However, the series actually explains how she gets away with it—the Order pays for some of the damages and also has to bribe the local media not to report on their involvement with the destruction.
Home Sweet Home: In the manga, after her adventures, Rosette returns back to the orphanage she grew up in and becomes a caretaker there.
In Vino Veritas: When Rosette gets drunk at a dinner party, she ends up being a "forceful drunk" (as Chrono notes), while also revealing anxiety over her shortened lifespan and worry over her brother.
I Will Wait for You: In the ending of the manga, Chrono promises Rosette that he'll return to her before going off to fight Aion in their final battle. For a reason that is never explained, he disappears for years, leaving her to wait for him even though their contract means that she doesn't have very long to live. After eight years he eventually does make it back to her right in time for her to die in his arms.
Kid with the Leash: Subverted and occasionally double subverted. Chrono usually doesn't need anyone to keep him on the straight-and-narrow. Usually.
Knight Templar Big Sister: When Rosette's little brother is kidnapped by Aion, she makes a Deal with the Devil and spends four years training as a Church Militant. The moment she discovers the location of her brother, she travels from New York to San Francisco, guns blazing, killing any demon that attempts to get in her way.
Meaningful Name: Rosette's last name is "Christopher" - that is, "Christ-bearer", which fits with her role as a demon fighter, but more importantly with her role as the reincarnation of Mary Magdalene.
Orphan's Ordeal: At first this is averted, but in the second half of the manga she occasionally admits in inner monologue that her parents' deaths did have an effect on her—she hates sitting and waiting because she was forced to while 'the adults' worked out her family's estate, for example.
Outdoorsy Gal: She wanted to be an explorer before Joshua was kidnapped.
To an almost equal extent, Rosette and Satella. They gripe almost constantly at one other, even after they become friends underneath the teasing.
Your Days Are Numbered: Symbolized by the watch she wears on her neck showing her remaining time alive. The mangaka explains in an Omake that the notion of having a limited time or lifespan is the main theme of the manga.
Zettai Ryouiki: In her militia outfit, she wears thigh-high stockings, leaving just a bit of tantilizing bare skin shown through the slits of her skirt.
Chrono is Sister Rosette's assistant and childhood friend. Although he appears to be a young boy of about twelve, he's actually a demon whose powers have been sealed away. The few that know what he really is tend to distrust him because of it, but he's a caring, lovable person who tends to get dragged into Rosette's messes. He and Rosette tend to have clashing personalities, but when it comes right down to it, she's the most important person in his life and he'd do anything to protect her.
Beast and Beauty: Chrono and Mary Magdalene play this trope straight. Chrono and Rosette are a little weirder about this, since by the time he meets her he's become much more gentle and calm (and he looks like a little kid).
Demon Lords and Archdevils: Chrono (along with a few others) is referred to as being very high "ranked" among the demons, implying he's particularly powerful and would've fallen under this trope had he not rebelled.
Detached Sleeves: The "gloves" Chrono wears under his coat are actually a bit closer to these the few times you see them without being covered up somehow.
Distinguishing Mark: His missing horns—he's even called "Chrono of the Broken Horn" at times. However, it's later revealed that Aion is missing his, too, which causes some confusion.
Establishing Character Moment: Chrono freaking out when he believes Rosette has been killed in battle in the second episode/chapter establishes how protective he is of Rosette, and the fact that he's a demon. In the manga, it also introduces the reader to his Fatal Flaw—his temper.
Fatal Flaw: Chrono's difficulties controlling his emotions, when combined with his demonic instincts, sometimes causes him to lose control and fight his enemies with a frightening unawareness to anything else. (Particularly in the manga.)
Go Out with a Smile: In the anime Chrono and Rosette's bodies are found together, both smiling.
Half-Human Hybrid: In the manga, sort of. Chrono was a human fetus but apparently born as a demon due to meddling with his mother when she was pregnant. He seems much more human than the typical demon.
In Vino Veritas: In a flashback that shows him drinking with Aion, Chrono shows a lot of regret over the battle that gave him the title "The Slayer of 100" and argues with Aion over how to respect the dead.
Pinocchio Nose: A subtle one in the manga—in the 7th volume, Chrono closes his eyes and puts on a strained smile when he realizes something's happened to Satella, then proceeds to start to babble about how they'll save Joshua soon while Rosette insists Chrono's being strange. A volume later, he once again closes his eyes and fakes a smile right before he freezes Rosette so she can't follow him.
Played straighter with Chrono and Aion. Chrono is emotional, bad with demonic technology and cares about people over everything else. Aion is coldly logical, shown playing chess, and sacrifices people he cares about for the success of his plan. However, the anime version switches the roles for them—a scene in a flashback shows Chrono silhouetted in blue, and Aion in red.
Rummage Sale Reject: If you seek out pictures of boy's clothing from the 1920's, Chrono's outfit isn't too far off from what a boy around his supposed age would wear...just with some added details that make him stand out from the crowd.
Savvy Guy, Energetic Girl: Chrono comes across as pretty calm and rational in comparison to Rosette (although he's a bit more impulsive and much more emotional when he doesn't have to balance her out).
Sharp-Dressed Man: Chrono's red suit is rather striking...although it's a bit more adorable than the typical look that follows this trope, since he's supposed to look like a 12 year old.
Shonen Hair: In his true form, and somewhat in his sealed form, too (only with a mullet-braid added onto the back).
A meek girl that was saved by Chrono and Rosette when her adoptive father attempted to use her holy powers for his own goals. Her powers have brought her nothing but misfortune, which has lead her to dislike them and caused her self-esteem issues. She admires Rosette and wants to grow up to be strong and confident like her.
Stepford Smiler: A mild version, since she feels like she's a burden to people she tries to keep smiling even when she's not happy. In the manga she seems to slowly start to become more comfortable with expressing her emotions.
This is apparently what otaku think housewives look like.
A prideful and elegant Bounty Hunter, Satella is the last to join Rosette's True Companions. Calling herself a "jewel witch", she's unaffiliated with the Order but ends up getting dragged into Rosette's mission once they cross paths. The heiress to a vast fortune, Satella starts off looking down at the Order's ways but soon starts to appreciate them more. She's cold and driven, but starts to open up to the others as they travel together.
In Vino Veritas: When Satella gets drunk at a dinner party she reveals that she's a shotacon by blatantly flirting with Chrono, then starts to wonder if she should give up on finding her family's killer.
Lady of War: Her fighting style can be pretty elegant and she comes across as much more mature than Rosette—although her hot temper sometimes causes her to charge into the fray and makes her something of a borderline example.
Ms. Fanservice: Particularly in the anime, but definitely in the manga, too.
Older Than She Looks: Satella might count for this in the manga epilogue, considering she's biologically still 19 in 1999 due to freezing herself in crystal.
Heartwarming In Hindsight: well of the In Hindsight tropes it fits the best, as she was frozen for so long she didn't experience World War II which made her safe from the discrimination Germans in USA went through at the time and no need for her to take sides.
Orphan's Ordeal: She probably has it the worst out of everyone, considering the nightmarish way she lost her family.
Younger than She Looks: Rosette is surprised when she finds out Satella is only 19. In an omake, the mangaka said he even got letters saying that Satella looked like a housewife.
The Magdalan Order
The Magdalan Order
Kicking ass for the Lord.
The Magdalan Order is a Christian organization dedicated to protecting people from demons. Although most of the members are humble servants of God, it's obvious that the Order is a powerful organization with the latest in technology and magical knowledge. They're connected enough that they can clean up Rosette's messes and keep her out of trouble with the law and the press.
Christianity is Catholic: Sorta. In the manga, the Magdalan Order is some form of "Anime Catholicism"—they have a lot of Catholic trappings, but priests in the Order can get married (as Joshua does), among other inconsistencies. The anime straightens it out by saying that the Order is a combined effort of several different denominations working together, so Rosette is technically not a nun and Remington is apparently a protestant minister. Many Fan Fic, however, makes the Order full-on stereotypical Catholic, with confessionals, rosaries and vows often popping up.
Church Militant: A religious organization whose purpose is to beat down on demons.
Rosette's superior in the Order. At first she comes across as aggressive and strict—particularly when dealing with Rosette, who tries her patience—but she's actually rather sweet if you show her common courtesy. It's clear that she loves her job and wants to protect people, but she can sometimes take a harsh approach to do it. Later in the series she shows a more thoughtful side as she grapples with the approaching darkness.
Father Ewan Remington is a member of the militia and Rosette's guardian. He was the one that originally asked her to join the Order, and takes the role of a father and mentor in her life. He's typically cheerful and carries himself with a cool sense of confidence, but when it comes time to fight he can be a deadly warrior. Whereas Sister Kate is strict and goes by the book, Father Remington often encourages Rosette to be a little more creative with how she solves her problems. He also spoils her rotten.
Badass Longcoat: Sort of, he's really wearing a jacket and a cassock, but it sure looks like this.
Big Damn Heroes: Remington tends to wait until the very last minute to help out.
Cool Sword: He's got a badass laser sword with holy powers.
Deadly Upgrade: In the manga, he's been implanted with demonic legion, which require constant "mantainance" to keep him alive.
Really 700 Years Old: He's at least seventy years old, but looks about thirty tops. In the anime, it's because he's a former angel while the manga has it that his body was infused with Legion, effectively making him 40% demon.
The inventor of much of the high-tech equipment and ammunition the Order uses. Earlier in the series he functions mostly as comic relief, creating wacky devices and behaving like an old pervert towards the nuns in the Order, but he does have a serious side which occasionally shows itself, and he's obviously a genius. He's taken Chrono somewhat under his wing and often stands up for him when others in the Order show distrust toward him.
A mysterious figure that's highly regarded by the Order, Mary was a holy woman that lived during the later half of the 19th century. She seems to have a connection to Chrono's past, although her story isn't told until later in the story.
All-Loving Hero: Gentle and constantly smiling, Mary shows kindness even to the demons who kidnapped her, becoming like family to them. She willingly helps them when a prophetic vision revealed to her that she would be killed by one of them. In the anime, they decided to make it obvious who she is by giving her stigmata, as well.
Arc Words: Her name shows up very early on and is even worked into the logo of the series, but we don't find out about who she really was until near the end.
Love Martyr: Mary Magdaline fell in love with Chrono despite knowing almost from the day she was born that he would eventually kill her. It's partially subverted in the manga, since Chrono inadvertantly killed Magdaline while trying to protect her, but was unfortunately unaware of the effects their Contract would have on her.
The race of supernatural beings that the Order fights against and that Chrono belongs to. Their origins and goals differ depending on whether you're following the manga or the anime, but both versions seem to be filled with proud warriors that look down upon humans and consider them tools at best.
Always Chaotic Evil: Subverted, they seem this way in the beginning but there's more going on behind the surface.
Ancient Astronauts: In the manga, demons are actually aliens stranded from their home world, although nearly all living demons have forgotten this.
Authority Equals Asskicking: In the manga, Duke Daffau is the leader of the Pursuers and (in Chrono's opinion at least) "the best of the best!" This might be the case in the anime as well, although he gets defeated pretty quickly in battle.
Bee People: In the manga, it's lampshaded by Chrono. The anime demons don't seem to fit this as well.
Bishonen Line: As a general rule, the more monstrous-looking and beast-like the demon is, the weaker they are.
Deal with the Devil: Contracts. Demons under contracts are bound to serve the person who makes the pact, but with a price — the demon uses the human's soul as an energy source in place of Astral energy.
Stripperiffic: A lot of the outfits we see demons wear expose a LOT of skin, particularly considering that many of the outfits we see appear to be what they're expected to wear in battle.
Sufficiently Advanced Aliens: The demons are a slightly less awe-inspiring version of this trope (but still seemingly supernatural) in the manga.
Voluntary Shapeshifting: The demons all have the ability to take on a human-looking form instead of their true demonic form, if they wish—although it appears that some have to hide inhuman body parts that don't transform, like cat ears or pig-like snouts.
Winged Humanoid: This seems like it might be a male-only ability, since neither Rizelle or Shader appear to have wings.
True Companions: They don't always get along, but it's clear that they all consider each other a sort of odd family. It's enough that in the manga, Chrono shows remorse for fighting them and even outward concern for them at times.
The Leader of the Sinners and the Big Bad of the series, Aion is a demon with ties to Chrono's past who is now at odds with him. He's charasmatic and smooth, but calculating and secretive. Since so much about him was kept a secret until later in the series, his personality and goals change drastically depending on if you're following the manga or the anime.
Animal Motifs: Aion has an eagle familiar that serves as his symbol (particularly in the anime), and he tends to be fond of bird-related similes as well.
Demon Lords and Archdevils: Both versions imply Aion was very high-ranked before his betrayal of Pandaemonium. The manga goes so far as to say that the Elders of his people expected him to become very high-ranked and powerful...and he exceeded their expectations.
Distinguishing Mark: Aion's missing horns is key to Satella eventually realizing that Aion was the one responsible for her parents' deaths.
Hotter and Sexier: The manga version of Aion doesn't seem too interested in sex, while the anime version delights in forcing passionate kisses on Rosette and generally acts like a Memetic Molester.
Incest Subtext: In the manga version, his hyper-focus on both Pandaemonium and Chrono comes across as being downright unhealthy once their relation to him is revealed. In the anime version, Chrono says Aion is "like a brother" to him, but in a flashback Aion pulls Chrono so close to him that they nearly kiss.
In Love with Your Carnage: Aion is very happy when Chrono flies into an Unstoppable Rage, and is often disappointed when Chrono tries to avoid tearing his enemies into a bloody pulp or expresses regret and disgust for his actions.
I've Come Too Far: In the manga, this is Aion's general rationalization for his continued efforts against Pandaemonium.
Karma Houdini: Aion appears to have gotten away with most of it in the anime, although the ending has been intepreted a few different ways. In the manga his fate is left ambiguous, but it's implied that Chrono defeated him.
Red Oni, Blue Oni: Possibly—Chrono has red eyes and clothing, and is emotional, bad with technology and places importance on people more than anything else. Aion has purple eyes and his clothes are also accented with purple, and he's cold, intelligent, and is willing to sacrifice anyone for his plan. However, the anime version reverses their colors in one scene, where Chrono is shown shillouetted in blue and Aion in red. It's possible this is because of the changes to their personalities—Chrono is portrayed as calmer than he is in the manga, and Aion is more easily swayed by his moods and impulses.
Scary Shiny Glasses: Aion's glasses don't seem to serve a purpose outside of this. Well, that and they make him look cool, plus it's possible they're there to hide from the audience that he has a face suspiciously similar to Chrono's.
He'll only be this calm for about a minute, so think fast.
Rosette's younger brother. As a child, Joshua was granted with a holy power that allowed him to heal others, but at the cost of his own health. Desperate to become stronger, Joshua accepted Aion's offer to wear Chrono's horns on his head—a gift that grants him incredible power, but at the cost of his sanity. Although fragments of his original cheerful, optimistic personality remain, his weak sanity and Aion's manipulation has twisted him into a childish, impulsive brat. He's wildly devoted to Aion, but greatly misses his sister.
The Atoner: The manga epilogue shows that Joshua joined the Order after returning home, with Azmaria guessing this as his reason.
Hero-Worshipper: Implied to be this way toward Aion...which may be just another symptom of the insanity caused by his horns. (Although it's at least justified by his previously established love of the occult and larger-than-life characters.) He showed hints of this to Chrono as a child, too.
Ill Boy: Joshua was one of these back when he was a child, which is what lead him to accept Chrono's horns from Aion.
Incest Subtext: Joshua becomes very obsessed with Rosette once he gets Chrono's horns. It doesn't help that in the anime version, Joshua often thinks that Fiore is his sister, despite a lot of the Ship Tease for them in the manga remaining in the anime.
Incurable Cough of Death: The price Joshua had to pay for his powers, along with seizures—until Aion gave him Chrono's horns...
Innocent Cohabitation: Joshua and Fiore live together by themselves for at least several months without anything appearing to happen between them. (besides a little bit of blood-drinking.)
Where I Was Born and Razed: When Joshua recieved Chrono's horns, he went mad from all the telepathic "noise" he could hear from the other orphans and "stopped the time" of everyone around them, freezing them in stone.
A quiet girl who serves as Joshua's maid. Although very stoic and polite, glimpses of a loving, devoted young woman can be seen behind her mask of stone. She tends to be a pushover, but God help you if you threaten Joshua—she's as devoted to him as he is to Aion.
Human Popsicle: Near the end of the manga, Satella freezes herself and Fiore in crystal.
Innocent Cohabitation: Joshua and Fiore live together by themselves for at least several months without anything appearing to happen between them. (Well, besides a little bit of blood-drinking anyway.)
Older Than She Looks: Fiore looks around 15, but she's actually probably closer to 25—she just hasn't aged since her death. In the manga epilogue, she still looks the same although she's now around 100 years old thanks to being frozen in crystal from 1924 to 1999.
The first member of the Sinners that Chrono and Rosette confront directly, Rizelle is a demon known as the "Puppetmaster". Although she can fight when cornered, she prefers to manipulate humans like puppets and use them to do her dirty work. She's desperate for attention from Aion.
Stripperiffic: In her demon form, she's basically wearing a leotard and thigh-high boots. (And her disguised form in the 1870s isn't much better.) Of course, this becomes Fan Disservice once her lower body is replaced with that of a large spider's...
An energetic Cat Girl demon that functions as the Sinner's techie. She rarely fights and prefers to stay on the sidelines—as she says, she "fights with her brain, not with her fists." In the manga she's very affectionate towards the other Sinners and seems to genuinely miss and worry about Chrono, but in the anime she has quite a sadistic streak.
Blush Sticker: Shader ALWAYS has these, even when she's upset or frightened.
A rough and tumble member of the Sinners who seems to style himself as some sort of cowboy. Genai is rude, crude and misoginistic. He not-so-secretly has a flame for Rizelle, so he's very bitter and angry towards anyone that had to do with her running off to confront Rosette.
Okay, so you can't really blame Gonzo for thinking he should be a mindless fighting machine.
The muscle of the Sinners. In the manga he's extremely loyal to Aion, but often serves as a voice of reason to the other sinners, and is portrayed as being something of a bookworm. In the anime, he...likes to punch things. And that's pretty much it.
Bad Guys Play Pool: Although they're never shown playing pool, Viede uses a pool metaphor to point out to Aion that he shouldn't go into battle without his sword.