Tropes associated with Casshern:
- The Atoner: Desperately trying to make up for ending the world.
- The Berserker: Casshern doesn't like fighting, but push him hard enough and he's liable to lose control and try to slaughter everything in sight, enemy or not.
- The Brute: Used to be a supersolider hit man for Braiking Boss, along with Dio and Leda.
- Bishōnen: The one who designed evidentially used a handsome young man as their model.
- Chick Magnet: Casshern certainly has a lot of women following him around and/or sighing over him during the course of the story. The list includes Lyuze, Sophita, Lizabel, Janice, Ringo and Nico, not to mention Leda also thinks he's beautiful. And then there's Luna...
- Driven to Suicide: Defied. He DID want to die and wanted Lyuze to kill him after the full force of him causing the Ruin hit him, but once she started doing some serious damage to him, his Berserk Mode wouldn't let her finish the job. She would have died if Friender didn't save her.
- Good Thing You Can Heal: Has a healing factor (which is incredibly painful to use for some reason) and gets injured far more often than any other character.
- The Grim Reaper: The finale has him deciding to metaphorically become death itself in his series' world so Luna and her subjects don't forget about death.
- High Collar of Doom: Subverted. He was every bit as evil as Dio and Leda, but not anymore.
- Heroic Safe Mode: It's still not clear what, exactly, his 'Berserk Mode' but it seems to be a "Combat Mode" of sorts that activates automatically whenever he enters a fight. Even if he chooses not to fight back, putting him under enough duress will also trigger it.
- Hero with Bad Publicity: Played for Drama. Casshern killed Luna and this brought the ruin for the world. Since everyone knows what happened, everyone hates him and want to kill him. Ringo is the only exception.
- Hyperspace Wardrobe: He's never actually seen either taking off or putting on his Cool Helmet. Who knows where it goes when he's not using it.
- Invincible Hero: Casshern was already the strongest robot before becoming immortal, so this should come as no surprise. The only times he ever gets defeated are when he’s actively seeking to get killed and even then, he still tends to win anyway by talking them down or his berserker mode activating. However, the focus of the show is never on the actual fighting and much more on the conflicts and motivations behind all it, so this trope is hardly detrimental to the series.
- Living Forever Is Awesome: Reconstructed in the final episode. By then he's come to believe that the fear of death is what makes people truly alive and so he decides to become death itself so Luna and her immortals don't become complacent.
- Marked Change: If his eyes suddenly light up and his facemask closes, run.
- My God, What Have I Done?: Makes this into an artform. Pushes him dangerously close to a Heroic B.S.O.D. more than once, as well.
- Person of Mass Destruction: He hates fighting, but once his Berserk Mode activates, he can rip entire armies to shreds with his bare hands without breaking a sweat.
- Who Wants to Live Forever?: His view is that the dispirited immortal robots—including himself—aren't truly alive, compared to the mortals who burn with the metaphorical "fire" of life.
Tropes associated with Lyuze:
- Action Girl: She fights and wins against other murderous robots.
- Amnesiacs Are Innocent: She let Casshern go the first time because she felt revenge wouldn't have been nearly as satisfying if Casshern didn't understand what he did.
- Badass Decay: An In-Universe, justified example. The Ruin weakens her body and makes her less able to fight, resulting in her being sidelined in the latter part of the series.
- Broke Your Arm Punching Out Cthulhu: Zig-zagged. She almost killed Casshern (even if he was actively trying to die at the time), but she eventually inflicted enough damage to trigger his Berserk Mode, and almost got herself killed shortly after. If Friender hadn't saved her, she would have never made it out alive.
- Dual Wielding: She has blades built into her arms.
- Love Redeems: Drops all antagonism towards Casshern after falling in love with him.
- The Only One Allowed to Defeat You: Delivered a Back Stab to Dio as he was about to finish Casshern off the first time, because she didn't want to be robbed of her shot at revenge. Later drops this entirely.
- Tsundere: Lyuze, once she decides she won’t kill Casshern just yet, begins showing a very gentle side to everyone but him, though at this point her hate for him has nothing to do with the affection of a tsundere. Of course, this all changes once they start traveling together and she falls in love with him, though she’s still a very mild example of a class B, and once she comes to terms with her feelings, and they sort it out, the violent streak goes completely away.
- Who Wants to Live Forever?: At first, she wanted Luna to save her from the Ruin. Once she sees how twisted she's become, she quickly changes her mind, deciding it's not worth it if it is going to change who she is. What she has learned while traveling with Casshern makes this decision final.
- Why Can't I Hate You?: See 'Tsundere.' She suffers a major internal conflict once she starts realizing she cares about Casshern and is torn between hating the person he was, and falling in love with the person he became post-amnesia. The fact that Casshern feels genuine remorse over everything he did makes it worse..
- You Killed My Father: The main reason she hates Casshern so much is he killed her sister pre-series.
Tropes associated with Ringo:
- Cheerful Child: In marked contrast to her grim surroundings, she is happy and her nature as a child is implied to be part of the reason why.
- Does Not Like Shoes: She wears them sometimes, but she takes them off to run barefoot on beaches and through fields whenever she can.
- Genki Girl: A peppy soul, in a bleak world.
- Infant Immortality: One of the few characters who survives the series.
- Morality Pet: To Casshern. The fact that she became utterly terrified of his robotic carnage in Berserk Mode and begged him to stop was what made him snap out of it.
- Raised by Grandparents: In the sense that Ohji was the one who created Leda, along with Dio and Casshern.
- She Is All Grown Up: Ringo is shown during the series' epilogue to have lived to her adult years. She's quite a looker, too.
Voiced by: Cho (Japanese), Jerry Russell (English)
Tropes associated with Ohji:
- Papa Wolf: He'll do anything to protect Ringo.
- Parental Substitute: He didn't create her but he's the closet thing Ringo has to a parent.
Voiced by: Kenji Utsumi (Japanese), J. Paul Slavens (English)
Tropes associated with Braiking Boss:
- A Father to His Men: Despite his actions, seems to care enough for his fallen robot troops to have graves dug for each and every one of them..
- The Emperor: His empire has fallen into total anarchy due to the Ruin, and he's now just another wanderer trying to survive.
- Evil Sounds Deep
- Hoist by His Own Petard: The fact that he was the one who ordered Luna's death makes his inevitable death at the hands of the Ruin his own fault.
- I Shall Taunt You: Does to to Vulcan. He falls for it hook, line, and sinker.Braiking Boss: Show me how mad you are.
- Kill All Humans: This guy is the reason humans are a rare sight in the Crapsack World.
- Nice Hat: He dons one for his fight with Casshern. He used to wear it all the time, until the Ruin happened.
- Pyrrhic Victory: Yes, he achieved his goal of defeating Luna... though at the cost of the Ruin spreading and infecting everyone including himself, his empire collapsing into anarchy, him losing most of his power, and almost every single one of his followers have lost whatever loyalty they had to him.
Tropes associated with Dio:
- The Ace: He is the only person in the entire series that can fight and win against Casshern, and he wins while in the middle of painfully dying. He is easily THE badass of Casshern Sins.
- Always Second Best: Casshern is superior to him in combat and other matters, and it drives him crazy. He so defines himself by defying this trope that as soon as he does, he has no reason to go on living.
- Battle Couple: Arguably with Leda, though she doesn't return his feelings until much later.
- Evil Counterpart: To Casshern. Though, Casshern used to be just as evil before his amnesia, if not more.
- Meaningful Name: "Dio" means "God" in several languages.
- Nothing Left to Do but Die: After achieving his life's goal and defeating Casshern.
- The Only One Allowed to Defeat You: To Casshern, to the point of obsession.
- White Hair, Black Heart: In contrast to Casshern, he wants to take over (what's left of) the world.
Tropes associated with Leda:
- Be Careful What You Wish For: Luna gives her the immortality she craves. It doesn't work out so well.
- Impaled with Extreme Prejudice: Luna kills her in this fashion.
- Love Redeems: Manipulated Dio's feelings for her throughout most of the series, until she genuinely began to feel the same way, and softened her personality a bit as a result.
- Missing Mom: Heavily implied to be Ringo's mother.
- Together in Death: After hearing how Dio's final wish was for Casshern to save Leda, she crawls back to his side to die with him.
- Vain Sorceress: Not so much a sorceress except in Techno Wizard sense but high emphasis on the "vain."
- White Hair, Black Heart: Like Dio, she wants to take over the remains of the world.
Tropes associated with Friender:
- Canine Companion: Of the robotic kind, and also counts as a Post-Apocalyptic Dog.
- The Immune: The Ruin doesn't affect him for some reason.
- Out of Focus: In most of the episodes, he's usually just background.
- Team Pet: Of the useful, kickass variety, who can generally be seen helping Casshern fight and/or snapping him out of his Unstoppable Rage.
Tropes associated with Luna:
- A God Am I: Grew a full-blown complex when she returned to power. She was worshiped before she died the first time, but she didn't revel in it nearly as much as she does now.
- Anti-Villain: She's a minor example of one because of philosophical differences between Casshern and his group. She's willing to give them her blood so they can live forever, but they decide they don't want to risk changing into one of her listless immortals.
- Bad Boss: She didn't stay with her longtime bodyguard as he lay dying because she considered his condition "disgusting". Poor Dune...However, note that he refused to drink her blood and save his life.
- Bitch in Sheep's Clothing: Post-resurrection Luna turns out to be this, having a disdain for everything affected by the Ruin, and death in general; she refuses to stay with her loyal bodyguard as he's dying, calling him disgusting.
- Came Back Wrong: Even though she's immortal and can't permanently die, she felt everything and was traumatized by Casshern killing her. Now she finds victims of the Ruin 'disgusting,' wants to abolish death itself, and even appears to be in love with Casshern. Then again... who isn't at this point?
- Dissonant Serenity: Her default expression is a look of quiet peace in the devastation brought by the Ruin.
- High Collar of Doom: Similar to Casshern, Leda, and Dio, only she's much less violent. Played straight later on.
- Impaled with Extreme Prejudice: How Casshern killed her. She gets better... physically, anyway.
- In Love with Your Carnage: Played with. She's a little too infatuated with Casshern, who brutally murdered her, but not because of the carnage itself.
- Karma Houdini: One of the few characters who survives the series until the very end. Justified due to her immortality, and probably because her dying a second time would lead to an even worse calamity than what her first death caused. In truth, this is a subversion since Casshern tells Luna that if she and her people forget death, he will come back, and definitely bringing death again. Luna won't be the same again.
- Kick the Dog: Does this to Dune, her bodyguard, by not staying with him as he died. This single action concisely demonstrates her post-resurrection meanness.
- Killer Rabbit: Not only did she regularly kill immortals in the past (even if she hated it and doing so eventually drove her crazy with guilt), she's the one who impales Leda after inflicting Body Horror on her.
- Living Forever Is Awesome: She literally wants to abolish death because she's disgusted by it. This is in stark contrast to what she did pre-series, which was to remove immortality, which made her feel like a murderer. In the final episode Casshern deconstructed this idea by pointing out that living is different from being alive, and the robots in her town were listless layabouts.
- Mysterious Waif: A young Emotionless Girl with god-like powers whose origins are never really explained.
- Names to Trust Immediately: "The Sun Named Moon," "Salvation." The truth depends on who you ask; everyone except Casshern and his group believe it to be true.
- Please Don't Leave Me: She makes this request of Casshern. They are one of the few instances in which her expression changes.
- Posthumous Character: Since she died pre-series, everything we know about her comes from others or from flashbacks. Then it turns out that she's Not Quite Dead.
- Stellar Name: Luna, thus "the Sun Named Moon".
- Took a Level in Jerkass: After her revival, she becomes nastier as a result of her death-trauma.
- Walking Spoiler: The fact that she's still alive in the main narrative is a big deal.
- We Can Rule Together: She proposes this to Casshern so they can rule all immortals as the metaphorical incarnations of life and death. After all that he's seen and been through, he naturally refuses.
- Well-Intentioned Extremist: Sure, she can fix the Ruin. She'll even throw in immortality. In exchange, she wants you to worship her as she slowly grows Drunk with Power and similar to Braiking Boss.
- Woman in White: Like Casshern, she is always dressed in immaculate white in this world of dust and grime.
- Yandere: Her tone and the look on her face during the aforementioned We Can Rule Together moment, not to mention when she makes a similar offer in the very beginning of Episode 21, screams this.Luna: "I want you to stay here with me forever, Casshern."
Voiced by: Yuto Nakano
Tropes associated with Dune:
- Heroic B.S.O.D.: After Luna's death. He starts to wander in the decay world screaming for Luna and wanting revenge against Casshern.
- Heroic Sacrifice: Sacrified himself in order to protect a single flower remembering how Luna liked flowers. Although there isn't much time for him anyway, since he was hit by the ruin.
- It's Personal: Casshern killed Luna and he wants revenge. It's subverted when Lyuze says Luna is alive.
- My Greatest Failure: He failed to protect Luna from Casshern; that's a big deal for a bodyguard.
- My Master, Right or Wrong: Part of his Undying Loyalty to Luna is never ever questioning her decisions.
- Revenge Before Reason: Dune barely had forces to fight due the ruin but he still wants his revenge killing Casshern.
- Roaring Rampage of Revenge: Two times, the first one moments after Casshern killed Luna and the second one after recognizing him in his second encounter with him.
- Say My Name: Screamed for Luna after seeing her being killed by Casshern.Dune: LUNAAAAA!
- Undying Loyalty: To Luna. He was her bodyguard before she was killed by Casshern. After knowing she is alive he reunited with her and supported all her actions, despite her becoming a villian and starting to treat him badly. He even sacrifices himself to protect something that she liked before.