History Characters / StevenUniverseBlueDiamond

* BigSisterBully: Gender-inverted and deconstructed. Her constant dismissal of Pink, combined with her refusal to let Pink [[spoiler:spare the Earth]], caused Pink to resent Blue and believe she never cared about her. In present day she seems to have [[HeelRealization realized this]], as she [[ItsAllMyFault blames herself]] for Pink's "death" and seems to have come to the conclusion that Pink was right about humanity not deserving to die. [[spoiler:[[Recap/StevenUniverseS5E26TogetherAlone "Together Alone"]] has her angrily telling "Pink" to "quit fooling around". This reaches its ultimate conclusion when Steven angers her to the point where she physically assaults him, leaving Steven to ask Blue how many times she locked Pink away, hurt her, and made her cry. [[HeelRealization This forces Blue to confront the fact that it was her abuse that drove Pink away in the first place, and that her claims of loving her fellow Diamond rang hollow in the face of her actions.]]]]
* BigSisterInstinct: Gender-inverted. In a flashback, Blue at least tries to thoroughly praise and encourage Pink Diamond in light of the rebellion, a stark contrast to Yellow refusing to speak and turning her back on the latter. It doesn't actually ''work'' [[spoiler:because she misunderstood Pink's motivation]] and comes off as CondescendingCompassion, but she gets points for trying, unlike Yellow, who was straight-out ignoring Pink. In [[Recap/StevenUniverseS5E25Familiar "Familiar"]], Blue notes that she always loved Pink's cheerful personality.

* AloofBigBrother: Gender-inverted and deconstructed. Not as much as Yellow, but she is shown to be condescending and hard towards Pink in [[Recap/StevenUniverseS5E17CantGoBack "Can't Go Back"]], though she ''tries'' to encourage her to be a good Diamond. [[Recap/StevenUniverseS5E19NowWereOnlyFallingApart "Now We're Only Falling Apart"]] even has her callously reject Pink's offer to [[spoiler:spare the Earth. Eventually, this is what made Pink believe that Blue never cared about her. [[Recap/StevenUniverseS5E26TogetherAlone "Together Alone"]] has her angrily telling "Pink" to "quit fooling around". Her actions drove Pink to fake her death in the Crystal Gems' rebellion (that she started herself), which has traumatized Blue so much that she remained deep in mourning for thousands of years. What makes this sadder is that Pink truly died giving birth to Steven, meaning that Blue or her surviving family could never apologize for their abusive actions]].

* AxeCrazy: Downplayed; while she's quite calm normally, her depression makes her very emotionally unstable when provoked-she is quite quick to [[HairTriggerTemper anger]] and DisproportionateRetribution. It's not yet clear if her violent anger was a result of losing Pink Diamond or not.

* BigBrotherBully: Gender-inverted and deconstructed. Her constant dismissal of Pink, combined with her refusal to let Pink [[spoiler:spare the Earth]], caused Pink to resent Blue and believe she never cared about her. In present day she seems to have [[HeelRealization realized this]], as she [[ItsAllMyFault blames herself]] for Pink's "death" and seems to have come to the conclusion that Pink was right about humanity not deserving to die. [[spoiler:[[Recap/StevenUniverseS5E26TogetherAlone "Together Alone"]] has her angrily telling "Pink" to "quit fooling around". This reaches its ultimate conclusion when Steven angers her to the point where she physically assaults him, leaving Steven to ask Blue how many times she locked Pink away, hurt her, and made her cry. [[HeelRealization This forces Blue to confront the fact that it was her abuse that drove Pink away in the first place, and that her claims of loving her fellow Diamond rang hollow in the face of her actions.]]]]
* BigBrotherInstinct: Gender-inverted. In a flashback, Blue at least tries to thoroughly praise and encourage Pink Diamond in light of the rebellion, a stark contrast to Yellow refusing to speak and turning her back on the latter. It doesn't actually ''work'' [[spoiler:because she misunderstood Pink's motivation]] and comes off as CondescendingCompassion, but she gets points for trying, unlike Yellow, who was straight-out ignoring Pink. In [[Recap/StevenUniverseS5E25Familiar "Familiar"]], Blue notes that she always loved Pink's cheerful personality.

* BlueIsHeroic: A [[DownplayedTrope downplayed]] [[InvertedTrope inversion]]. Her ''only'' color is blue and her name is literally "''Blue'' Diamond", but she's an AntiVillain who, despite her unsavory traits, starts out as the most sympathetic of the Diamonds [[spoiler:who eventually realizes the physical/emotional harm she had caused everyone and [[HeelFaceTurn becomes genuinely good]]]].

** While it's left up in the air how much of it is due to grief, her modern appearance suggests she has changed a ''lot'' since the Rebellion and Pink Diamond's death. [[spoiler:She's also far kinder and more considerate towards Steven than she was in flashbacks to Pink. However, once everyone returns to Homeworld after finding "Pink Diamond", Blue reverts to her old aloof, controlling behavior by expecting Steven to host a royal ball exactly to the Diamonds' standards, and when Steven breaks protocol by dancing and fusing with Connie into Stevonnie, Blue ''threatens'' to unfuse them herself. In [[Recap/StevenUniverseS5E28ChangeYourMind "Change Your Mind"]], Blue briefly reaches her RageBreakingPoint and ''blasts'' Steven with an energy beam, before Steven's ArmorPiercingQuestion makes her [[HeelRealization realize what]] [[MyGodWhatHaveIDone she's doing]] and transition into a full HeelFaceTurn]].

* CoolBigSis: What she'd like to believe regarding Pink Diamond, but ultimately a subversion. [[spoiler:While she was closer and more affectionate to Pink than the other Diamonds, and she did try to encourage her, it's revealed later that she had inadvertently emotionally abused her one time too many as well, by locking her up in a tower and later berating her when she made a mistake, ignoring her wish to preserve Earth's living inhabitants, and making her a [[PuppetKing Puppet Queen]]. It's also implied she may have used her [[EmotionBomb emphatic abilities]] to make Pink cry too. This, along with Yellow's [[AloofBigSis strictness]] all culminated Pink's belief that Blue and Yellow didn't truly love her and partially resulted in Pink rebelling against them as Rose Quartz. Blue redeems herself when she realizes how terrible she was to Pink, and resolves to help Steven and Connie escape Homeworld as atonement.]]

* HeavenlyBlue: She is, as her name implies, blue, resembles the Virgin Mary, has blue light attacks and is worshipped as a god. [[LightIsNotGood She is, however, an antagonist.]] [[spoiler:For most of the series, anyway.]]

** [[spoiler:Unlike Yellow, she seems to have realized she and Yellow were too [[BigBrotherBully callous and cruel]] to Pink, to the point of [[ItsAllMyFault blaming herself for her apparent demise]]. When she realized Steven is Pink (in a sense), she stops her rampage and shows she really ''has'' changed, being far kinder and more considerate to him and what he wants.]] Though this also turns out to be downplayed in that it's clear she hasn't fully learned from her mistakes, and is still prejudiced towards humans and the Crystal Gems.

* LaserGuidedKarma: [[spoiler:Because Blue was [[BigBrotherBully emotionally abusive and condescending]] towards Pink, the latter stages a rebellion against Homeworld and [[FakingTheDead faking her death]], causing Blue to grieve for millennia. Following the return of Pink's son Steven to Homeworld, Blue, seeing him as Pink, becomes eager to renew her familial bond with him only to revert back to her aloof behavior towards him, but it doesn't take long for him to (in Blue's view, anyway) turn out to be even ''worse'' than Pink, much to Blue's distress. It only takes Steven [[CallingTheOldManOut convincing her that her behavior was wrong]] for her to ''finally'' realize the flaws of Homeworld and the Diamonds — the kicker is since Pink Diamond is truly dead, she can never personally apologize to her littlest fellow Diamond for what she had done.]]

** Her desire to preserve Pink Diamond's legacy includes keeping the humans in the Zoo well cared for and keeping the Earth Quartzes and other Rose Quartzes alive (even if the latter are bubbled), both of which Yellow Diamond finds absurd. She also [[DramaticIrony intended]] [[YouWillBeSpared to save Greg]] by kidnapping him and taking him to the Zoo.

* EnergyWeapon: Her primary attack in [[Recap/StevenUniverseS5E23Reunited "Reunited"]] is to [[StatusEffects slow down the Crystal Gems]] with {{Emotion Bomb}}s and summoning self-directing {{Hand Blast}}s to barrage the battlefield.

* EnergyWeapon: Her primary attack in [[Recap/StevenUniverseS5E23Reunited "Reunited"]] is to [[StatusAilment slow down the Crystal Gems]] with {{Emotion Bomb}}s and summoning self-directing {{Hand Blast}}s to barrage the battlefield.

* StatusAilment: Her {{Emotion Bomb}}s act as this in a battle situation, overwhelming every gem on the beach with overwhelming sadness and defusing Alexandrite in [[Recap/StevenUniverseS5E23Reunited "Reunited"]].

[[/folder]]

[[folder:A-D]]

[[/folder]]

[[folder:E-H]]

[[/folder]]

[[folder:I-L]]

[[/folder]]

[[folder:M-O]]

[[/folder]]

[[folder:P-S]]

[[/folder]]

[[folder:T-Y]]

* {{Foil}}: To her fellow Diamond, Yellow. Aside from their colors and masculine/feminine personalities, Blue Diamond constantly and obsessively mourns Pink Diamond, collecting everything related to her to preserve Pink's memory, and is so utterly consumed by her own depression that she neglects her duties as ruler of Homeworld.

* NotSoDifferent:
** Greg saw Blue Diamond's loss of Pink Diamond as no different than his loss of Rose. Their experiences with the death of a loved one allowed both of them to bond; what's more, Blue kneels down to look at Greg at eye-level more or less as this happens, which is in its own way acknowledging this trope.
** She's also this to Pearl (at the beginning of the series): both are trying to cope with the death of their loved one in the same way, by constantly grieving and refusing to move on.
*** [[spoiler:Ironically, Greg's, Pearl's and Blue Diamond's loved ones are all the same individual.]]
** To Amethyst (post-Gem War). Both are considered the lazy, undisciplined members of their team, lacking proper motivation to work with others due to unresolved emotional growth (Amethyst's inferiority complex being an Earth-born gem and defective, Blue Diamond believing Pink Diamond had died in what may have been a preventable tragedy) and have developed counter-dependent attitudes towards anyone that pushes them over it (Pearl/Yellow).

[[Characters/StevenUniverseCrystalGems Crystal Gems]] ([[Characters/StevenUniverseStevenQuartzUniverse Steven Quartz Universe]] | [[Characters/StevenUniverseGarnet Garnet]] | [[Characters/StevenUniverseAmethyst Amethyst]] | [[Characters/StevenUniversePearl Pearl]] | [[Characters/StevenUniverseRoseQuartz Rose Quartz]] | [[Characters/StevenUniverseConnieMaheswaran Connie Maheswaran]] | [[Characters/StevenUniversePeridot Peridot]] | [[Characters/StevenUniverseLapisLazuli Lapis Lazuli]]) | [[Characters/StevenUniverseGemFusions Gem Fusions]] | [[Characters/StevenUniverseHomeworldGems Homeworld Gems]] | [[Characters/StevenUniverseDiamondAuthority Diamond Authority]] ([[Characters/StevenUniverseYellowDiamond Yellow Diamond]] | '''Blue Diamond''' | [[Characters/StevenUniversePinkDiamond Pink Diamond]] | [[Characters/StevenUniverseWhiteDiamond White Diamond]]) | [[Characters/StevenUniverseYellowDiamondsCourt Yellow Diamond's Court]] ([[Characters/StevenUniverseJasper Jasper]]) | [[Characters/StevenUniverseBlueDiamondsCourt Blue Diamond's Court]] | [[Characters/StevenUniverseSpinel Spinel]] | [[Characters/StevenUniverseOffColors Off Colors]] | [[Characters/StevenUniverseGemMonsters Gem Monsters]] | [[Characters/StevenUniverseLittleHomeworld Little Homeworld]] | [[Characters/StevenUniverseHumans Humans]] ([[Characters/StevenUniverseGregUniverse Greg Universe]] | [[Characters/StevenUniverseLarsBarriga Lars Barriga]] | [[Characters/StevenUniverseSadieMiller Sadie Miller]]) | [[Characters/StevenUniverseOther Other]] | [[Characters/StevenUniverseS1E33GarnetsUniverse Garnet's Universe]]]]-]]]

** Her grief for her fellow Diamond Pink echoes what most parents fear — losing one's child, and the struggle to move on from it. Moreover, in [[Recap/StevenUniverseS5E2TheTrial "The Trial"]], while confronting "Rose" (actually Steven claiming to be her), she acts like an angry, grieving mother who wants justice for Pink's murderer.

** Seen again in [[spoiler:[[Recap/StevenUniverseS5E23Reunited "Reunited"]]. She's a ''terrifyingly'' capable warrior, using her emotion-based powers to effortlessly incapacitate the entire Crystal Gem team. It was only Lapis Lazuli, whose [[DisabilityImmunity extremely tragic past made her immune to Blue's grief wave]], that allowed them to temporarily stun her. And even then, she was back up in seconds.]]

!!!'''Voiced by:''' Music/LisaHannigan

* FrickinLaserBeams: Her primary attack in [[Recap/StevenUniverseS5E23Reunited "Reunited"]] is to [[StatusAilment slow down the Crystal Gems]] with {{Emotion Bomb}}s and summoning self-directing {{Hand Blast}}s to barrage the battlefield.

** This seems to be a subversion after [[Recap/StevenUniverseS5E2TheTrial "The Trial"]], where Blue isn't just grieving, she's unable to accept the official story of her beloved sibling's demise — ''because it makes no sense''. The questions "How could Rose do it?" and "How ''did'' Rose do it?" are tearing her up inside. This, coupled with the fact that Yellow is uninterested in finding the truth, is causing her even more distress. A real-world equivalent would be a grieving person whose family member was murdered [[NeverFoundTheBody but they never located their family member's dead body]]. Little wonder Blue is unable to move on.

* ForYourOwnGood: When Pink was reluctant to continue with the Earth colony, she and Yellow directly intervened. She was quite vocal about it, wanting her younger sibling to be as successful as them.

* {{Foil}}: To her fellow Diamond, Yellow Diamond. Aside from their colors and masculine/feminine personalities, Blue Diamond constantly and obsessively mourns Pink Diamond, collecting everything related to her to preserve Pink's memory, and is so utterly consumed by her own depression that she neglects her duties as ruler of Homeworld.

** This trope is ZigZagged between her and Yellow in the present day during Steven's trial. While Blue does act like a depressed {{NEET}}, at the very least she's insistent on continuing the trial properly. Yellow, on the other hand, while determined to keep her forces in line, treats the trial like a KangarooCourt.

* LaserGuidedKarma: [[spoiler:Because Blue was [[BigBrotherBully emotionally abusive and condescending]] towards Pink, the latter stages a rebellion against Homeworld and [[FakingTheDead faking her death]], causing Blue to grieve for millennia. Following the return of Pink's son Steven to Homeworld, Blue, seeing him as Pink, becomes eager to renew her sister-like bond with him only to revert back to her aloof behavior towards him, but it doesn't take long for him to (in Blue's view, anyway) turn out to be even ''worse'' than Pink, much to Blue's distress. It only takes Steven [[CallingTheOldManOut convincing her that her behavior was wrong]] for her to ''finally'' realize the flaws of Homeworld and the Diamonds — the kicker is since Pink Diamond is truly dead, she can never personally apologize to her littlest fellow Diamond for what she had done.]]

* ParentalSubstitute: One possible interpretation of her relationship with Pink Diamond. Considering there's a chance White Diamond created Yellow, Blue, and Pink by splitting parts of herself off in an attempt to rid herself of self-perceived imperfections, the two are, more-or-less, "sisters" with Pink implied to have been the youngest. Since someone had to teach Pink how to behave like a Diamond with White withdrawn into solitude in her own headship and Yellow burying herself in her work most of the time in a vain attempt to impress White, the role was left largely to Blue. [[OutlivingOnesOffspring This makes Blue's grieving even more tragic.]]

* SelfServingMemory: She tells Greg that she and Pink Diamond were "very close", [[spoiler:yet Blue's constant dismissal of Pink, combined with her refusal to let Pink spare the Earth, suggests that their relationship was strained ''at best''. In fact, the only on-screen interactions between Blue and Pink when the latter was still alive have been fairly negative. "Now We're Only Falling Apart" even has Pink, as Rose, regretting leaving Garnet with Blue, implying that she sees Blue as more of a tyrant than a sister. It apparently got so bad that even thousands of years after faking her death, Pink didn't miss Blue at all.]]

* TragicKeepsake: Blue Diamond sees anything related to her dead "sister" Pink Diamond as something to preserve and keep around her. She keeps everything from Pink Diamond's empty throne room and the bubbled gems of her former Rose Quartz servants, to the Human Zoo and the Quartzes from the Earth Kindergardens. When Greg, a human from Earth, shows her compassion, Blue Diamond decides to take him, too, in order to save what she believes to be "one last piece of [Pink Diamond's] legacy" from the Cluster. Yellow Diamond derides Blue Diamond's habit of collecting anything related to Pink Diamond as useless clinging to the past. In "Reunited", [[spoiler:when she sees the surviving Crystal Gems and "Rose Quartz" still living on Earth, she is ''furious'', seeing it as a grave affront to Pink's memory]].

* VillainHasAPoint: While she's obviously trying to [[spoiler:murder Steven during "The Trial", she is right that the court has to observe the formalities, like the defense lawyer and defendant being allowed to make a statement, and said lawyer providing evidence of Rose Quartz's possible innocence. The formalities in fact reveal a lot of holes in Pink's death. Blue has been sensing all is not right with the official story and prods him, demanding answers. And considering she thinks that Steven murdered her little sister, it's actually really merciful of her to correct him on the details of the murder, angry and sad as she is.]]

* WhatYouAreInTheDark: She secretly kept visiting Pink Diamond's ruined palanquin on Earth at the site of her shattering thousands of years after the Rebellion, knowing Yellow Diamond wouldn't approve of her being in a place where their 'sister' was killed by a Homeworld traitor.

** She's highly revered by her Homeworld subjects, but behind closed doors she's a sad and depressed woman who's in perpetual mourning over her dead "sister" Pink Diamond and wallowing in her own guilt over her failure to prevent her death.

* WoobieDestroyerOfWorlds: When we see her in the present day, she is obsessed with her grief over Pink Diamond, trying to gain closure from looking for answers on how exactly her 'sister' died and who did it.

* HairTriggerTemper: Ironically, Blue Diamond's temper can be even ''worse'' than Yellow Diamond's. It took one of her followers calling her what is probably the equivalent of a Gem slur, and in another case, being accused of murdering her own sister, for Yellow to finally snap and get violent. Blue, on the other hand, was immediately ready to shatter one of her own Gems for accidentally fusing with one of her elites, and totally lost her composure because "Rose Quartz" apparently didn't want to remember the most traumatic event in her life. As mentioned above in AxeCrazy, it's unclear if her violent anger is as a result of Pink Diamond's [[spoiler:supposed]] shattering. [[Recap/StevenUniverseS5E19NowWereOnlyFallingApart "Now We're Only Falling Apart"]] implies that she was like this beforehand considering how [[spoiler:Pink Diamond express fear and guilt for leaving Garnet at her mercy, which makes her change her goal from scaring Homeworld off of Earth to making it a home for outcast Gems]].

* LaserGuidedKarma: [[spoiler:Because Blue was [[BigBrotherBully emotionally abusive and condescending]] towards Pink, the latter stages a rebellion against Homeworld and [[FakingTheDead faking her death]], causing Blue to grieve for millennia. Following the return of Pink's son Steven to Homeworld, Blue, seeing him as Pink, becomes eager to renew her sister-like bond with him only to revert back to her aloof behavior towards him, but it doesn't take long for him to (in Blue's view, anyway) turn out to be even ''worse'' than Pink, much to Blue's distress. It only takes Steven [[CallingTheOldManOut convincing her that her behavior was wrong]] for her to ''finally'' realize the flaws of Homeworld and the Diamonds — the kicker is since Pink Diamond is truly dead, she can never personally apologize to her little "sister" for what she had done.]]
* LeanAndMean: In her initial appearance, she is veiled, ambiguously threatening with long, lean arms, and is perfectly willing to crush Ruby's gem more for accidentally fusing with Sapphire than allowing the rebels to escape. In the present, this is {{subverted|Trope}} as she is more traditionally feminine-looking than her "sister" Yellow Diamond with a fuller, more hourglass shape. Whether this is due to Garnet being an UnreliableNarrator in [[Recap/StevenUniverseS2E25TheAnswer "The Answer"]] or due to a regeneration in the intervening millennia is yet to be known. [[spoiler:After experiencing a HeelRealization, she decides to [[HeelFaceTurn avert it]] and help Steven and Connie get to White Diamond.]]

* MoralMyopia: Blue Diamond had no moral qualms about ordering Ruby's execution, suggesting that she has a harsh standard for Gems that disobey her rules. However, when her sister Pink Diamond was killed, she mourned for ''centuries''.

* PushoverParents: Downplayed. Her younger sister Pink was able to invent excuses for Blue to let her out of the prison tower, and Blue would cave and let her out. In [[Recap/StevenUniverseS5E28ChangeYourMind "Change Your Mind"]], Yellow calls her out for constantly bending the rules for Pink.

* RevengeBeforeReason: Subverted. We're led to believe that she wants to avenge Pink in "The Trial", given she wants to do ''something'' terrible to Rose. It turns out, however, that Blue wants answers more than revenge: ''how'' did her sister die, and ''why'' is the official story full of holes?

** Her grief for her "sister" Pink echoes what most parents fear — losing one's child, and the struggle to move on from it. Moreover, in [[Recap/StevenUniverseS5E2TheTrial "The Trial"]], while confronting "Rose" (actually Steven claiming to be her), she acts like an angry, grieving mother who wants justice for Pink's murderer.

* BigBrotherBully: Gender-inverted and deconstructed. Her constant dismissal of Pink, combined with her refusal to let Pink [[spoiler:spare the Earth]], caused Pink to resent Blue and believe she never cared about her. In present day she seems to have [[HeelRealization realized this]], as she [[ItsAllMyFault blames herself]] for Pink's "death" and seems to have come to the conclusion that Pink was right about humanity not deserving to die. [[spoiler:[[Recap/StevenUniverseS5E26TogetherAlone "Together Alone"]] has her angrily telling "Pink" to "quit fooling around". This reaches its ultimate conclusion when Steven angers her to the point where she physically assaults him, leaving Steven to ask Blue how many times she locked Pink away, hurt her, and made her cry. [[HeelRealization This forces Blue to confront the fact that it was her abuse that drove Pink away in the first place, and that her claims of loving her sister rang hollow in the face of her actions.]]]]

* DramaticallyMissingThePoint: The Human Zoo that was kept in Pink's name? [[spoiler:That was created by Blue, because she misunderstood Pink's desire to preserve Earth]]. And she genuinely thought that [[spoiler:her and Yellow's decision to make Pink a puppet ruler of Earth would help shield her sister from the more difficult aspects of ruling, since she interpreted Pink's excuses as her having a hard time with colonizing Earth. It all backfired ''spectacularly'']].

** This seems to be a subversion after [[Recap/StevenUniverseS5E2TheTrial "The Trial"]], where Blue isn't just grieving, she's unable to accept the official story of her beloved sibling's demise — ''because it makes no sense''. The questions "How could Rose do it?" and "How ''did'' Rose do it?" are tearing her up inside. This, coupled with the fact that Yellow is uninterested in finding the truth, is causing her even more distress. A real-world equivalent would be a grieving person whose sister was murdered [[NeverFoundTheBody but they never located their family member's dead body]]. Little wonder Blue is unable to move on.

* {{Foil}}: To her "sister", Yellow Diamond. Aside from their colors and masculine/feminine personalities, Blue Diamond constantly and obsessively mourns Pink Diamond, collecting everything related to her to preserve Pink's memory, and is so utterly consumed by her own depression that she neglects her duties as ruler of Homeworld.

** In "Homeworld Bound", it's shown [[spoiler:she regrets using her powers to make others feel the pain ''[[ItsAllAboutMe she]]'' feels, and is now bringing joy to others via clouds that her new power create.]]

* AloofBigSister: Not as much as Yellow, but she is shown to be condescending and hard towards Pink in [[Recap/StevenUniverseS5E17CantGoBack "Can't Go Back"]], though she ''tries'' to encourage her to be a good Diamond. [[Recap/StevenUniverseS5E19NowWereOnlyFallingApart "Now We're Only Falling Apart"]] even has her callously reject Pink's offer to [[spoiler:spare the Earth. Eventually, this is what made Pink believe that Blue never cared about her. [[Recap/StevenUniverseS5E26TogetherAlone "Together Alone"]] has her angrily telling "Pink" to "quit fooling around".]]

* BigBrotherBully: A gender-inverted, unwitting example. Her constant dismissal of Pink, combined with her refusal to let Pink [[spoiler:spare the Earth]], caused Pink to resent Blue and believe she never cared about her. In present day she seems to have [[HeelRealization realized this]], as she [[ItsAllMyFault blames herself]] for Pink's "death" and seems to have come to the conclusion that Pink was right about humanity not deserving to die. [[spoiler:[[Recap/StevenUniverseS5E26TogetherAlone "Together Alone"]] has her angrily telling "Pink" to "quit fooling around". This reaches its ultimate conclusion when Steven angers her to the point where she physically assaults him, leaving Steven to ask Blue how many times she locked Pink away, hurt her, and made her cry. [[HeelRealization This forces Blue to confront the fact that it was her abuse that drove Pink away in the first place, and that her claims of loving her sister rang hollow in the face of her actions.]]]]

** [[spoiler:Unlike Yellow, she seems to have realized she and Yellow were too [[BigSisterBully callous and cruel]] to Pink, to the point of [[ItsAllMyFault blaming herself for her apparent demise]]. When she realized Steven is Pink (in a sense), she stops her rampage and shows she really ''has'' changed, being far kinder and more considerate to him and what he wants.]] Though this also turns out to be downplayed in that it's clear she hasn't fully learned from her mistakes, and is still prejudiced towards humans and the Crystal Gems.

* LaserGuidedKarma: [[spoiler:Because Blue was a BigSisterBully towards Pink, the latter stages a rebellion against Homeworld and [[FakingTheDead faking her death]], causing Blue to grieve for millennia. Following the return of Pink's son Steven to Homeworld, Blue, seeing him as Pink, becomes eager to renew her sister-like bond with him only to revert back to her aloof behavior towards him, but it doesn't take long for him to (in Blue's view, anyway) turn out to be even ''worse'' than Pink, much to Blue's distress. It only takes Steven [[CallingTheOldManOut convincing her that her behavior was wrong]] for her to ''finally'' realize the flaws of Homeworld and the Diamonds — the kicker is since Pink Diamond is truly dead, she can never personally apologize to her little "sister" for what she had done.]]

* BigSisterBully: Not physically or intentionally, but her constant dismissal of Pink, combined with her refusal to let Pink [[spoiler:spare the Earth]], led Pink to dislike Blue and believe she never cared about her. In present day she seems to have [[HeelRealization realized this]], as she [[ItsAllMyFault blames herself]] for Pink's "death" and seems to have come to the conclusion that Pink was right about humanity not deserving to die. [[spoiler:[[Recap/StevenUniverseS5E26TogetherAlone "Together Alone"]] has her angrily telling "Pink" to "quit fooling around". This reaches its ultimate conclusion when Steven angers her to the point where she physically assaults him, leaving Steven to ask Blue how many times she locked Pink away, hurt her, and made her cry. [[HeelRealization This forces Blue to confront the fact that it was her abuse that drove Pink away in the first place, and that her claims of loving her sister rang hollow in the face of her actions.]]]]
* BigSisterInstinct: In a flashback, Blue at least tries to thoroughly praise and encourage Pink Diamond in light of the rebellion, a stark contrast to Yellow simply turning her back on the latter. It doesn't actually ''work'' [[spoiler:because she misunderstood Pink's motivation]] and comes off as CondescendingCompassion, but she gets points for trying, unlike Yellow, who was straight-out ignoring Pink. In [[Recap/StevenUniverseS5E25Familiar "Familiar"]], Blue notes that she always loved Pink's cheerful personality.

* SouthPaw: Blue nearly always uses her left hand, and her ship is even a left arm.

* {{Adorkable}}: [[WhenSheSmiles When she's happy]] she tends to become this.
** In [[Recap/StevenUniverseS4E10StevensDream "Steven's Dream"]] she cheers up after she has a meaningful conversation with Greg during one of her secret visits to Pink's shattering site. The way she talks about how she shouldn't even be on Earth is similar to a teenager who snuck out of the house at night, something she doesn't want her "mother" and "older sister" to know about, and when she finally decides to [[ImTakingHerHomeWithMe take Greg back with her]] she has a downright goofy smile on her face, and doesn't notice she's [[AndCallHimGeorge holding Greg too tightly]].
** In [[Recap/StevenUniverseS5E24LegsFromHereToHomeworld "Legs From Here to Homeworld"]], [[spoiler:she looks just adorable when crying TearsOfJoy over Pink [[NotQuiteDead still being alive]] (in a sense) and nuzzling Steven against her cheek, but she again doesn't notice that she [[AndCallHimGeorge is squishing him just a bit]]. She also seems to become amused by Steven's curiosity around things he should know about as "Pink" and cracks a few smiles at Yellow's growing frustration over the entire thing.]]
** In [[Recap/StevenUniverseS5E25Familiar "Familiar"]], [[spoiler:she's absolutely delighted to see Steven again because Pink always made her happy, and there is no change from the way Pink acted thousands of years ago to how Steven acts presently. The only difference she notes is calling "Pink" Steven now, which she precedes to say multiple times with emphasis on different syllables because she thinks it sounds funny.]]
** In [[Recap/StevenUniverseS5E28ChangeYourMind "Change Your Mind"]], when Connie mentions being grounded before, Blue is absolutely baffled by what the human is talking about. [[spoiler:Later after being told by White to [[GoToYourRoom go to their rooms]], Blue, still not understanding the concept of being grounded, [[LiteralMinded asks what rooms she and the others should go to]], and later swears to White that [[NotMeThisTime it wasn't her]] when her and Yellow's ships punch White's.]]

* WhenSheSmiles: When she breaks out of her depression and smiles, her more elegant and regal features allow her to come off as endearing albeit a tad {{Adorkable}}. She also becomes more self-assertive and active whenever she isn't sad [[spoiler:as when she found out about Pink's shattering being fake, she cried less and became motivated in helping Steven take Pink's place on Homeworld instead of neglecting her duties like she had before.]]

* BlueIsHeroic: A [[DownplayedTrope downplayed]] [[InvertedTrope inversion]]. Her ''only'' color is blue and her name is literally "''Blue'' Diamond", but she's an AntiVillain.

-->'''Blue Diamond: You cannot fathom how much I've mourned! What thousands of years of grief has done to me!

* {{NEET}}: PlayedForDrama; while she is one of distinguished Gems that command everything on Homeworld and other Gem-controlled planets, Blue nowadays does nothing but wallow in her own grief, something Yellow Diamond calls her out on.

* CoolAunt: [[spoiler:After realizing Steven is technically Pink, she becomes far kinder, more supportive, and considerate towards him than she was to Pink. Where Yellow still has some harshness towards him, Blue is quick to come to his defense and instantly jumps in to try and help heal Centipeetle — when Yellow near instantly writes it off as a lost cause — because it's important to "Pink". [[Recap/StevenUniverseS5E25Familiar "Familiar"]] briefly has her calling him "Steven" instead of "Pink".]]
** [[spoiler:And then there's her HeelFaceTurn in [[Recap/StevenUniverseS5E28ChangeYourMind "Change Your Mind"]], which has her fully acknowledge him as his own being and she even fights Yellow to protect him.]]