Dusk Golem
A 21st Century Rockefeller
Posting my theory here:
I know the obvious culprit is Yellow Diamond, and it could be White Diamond because we know very little about her, or hell you could argue it was some conspiracy and Pink Diamond wanted it, but I honestly think Blue Diamond did it. I would even say it's been subtly foreshadowed since Season 2 of the show.
PIECE OF EVIDENCE ONE: In The Answer, we see that Blue Diamond was on Earth. We also see in the crowds the gems present are all blue/pink colored. It's also established that Blue Diamond was establishing a colony on Earth in this episode (that's why Pearl arrives to stop Blue Diamond's colonization), there is no mention of Yellow Diamond having any involvement with Earth and moreso it seems Yellow Diamond just wants to get rid of the planet. But it's confirmed both Pink and Blue diamond were on Earth, and Blue Diamond was trying to establish a colony on Earth.
(side note: It's easy to feel empathetic for Blue Diamond, but you must remember she's not a good person. There's a reason Garnet fears her, and the Blue-based gems almost seem particularly troubled.)
PIECE OF EVIDENCE 2: Steven, who is and isn't Rose Quartz, is shown to have a particularly strong connection to Blue Diamond in Steven's Dream. On the opposite side of the planet he see's from Blue Diamond's perspective in his dreams and begins to cry her tears. The only people Steven see's the dreams of are those he is close to, yet he doesn't know Blue Diamond, implying that Rose Quartz was close to Blue Diamond. Blue Diamond can create an aura that makes all nearby people cry, but this happens within a radius that wouldn't spread to the other side of a planet, and specifically only Steven is crying when she's on Earth and not the other Gems. Through this a connection between Rose Quartz and Blue Diamond can be established. And it's notable Steven only responds in this way to Blue Diamond, and responds to it when no one else is responding to it.
PIECE OF EVIDENCE 3: In the same episode, Steven's Dream, the first line we hear Diamond muttering to herself in front of Pink's vehicle is how she's sorry, so sorry. She says she thinks this is still Pink's planet. Greg asks if Blue Diamond was close with Pink, to which there's a zoom-in on Blue Diamond's face when she says, "Very." As we establish in The Trial, the person who shattered Pink Diamond was someone very close to her.
PIECE OF EVIDENCE 4: Blue Diamond seems especially interested in preserving Pink Diamond's legacy. Something that doesn't make sense here: Pink Diamond was a threat to humanity and the Crystal Gems were fighting her for protection of Earth, Pink Diamond wasn't on the Crystal Gems side. So why does Blue Diamond have such an invested interest in protecting humanity and preserving it (and even keeping Pink's bubbled gems, who Pink would've probably gotten around to shattering anyways as they were rebels to her?) and what Pink Diamond stood for? Could there be a chance Blue Diamond believed in what Pink Diamond had initially stood for but not where her actions were headed so she chose to preserve Pink's legacy?
PIECE OF EVIDENCE 5: Yellow Diamond is very blunt, she is presented as being very straight-forward. She will get what she wants no matter the means and doesn't seem to hide her feelings or intent, she will publicly destroy her enemies and make a show of it, not keep it in the shadows. She won't let herself fret over things, she is malicious but she's certainly not presented as someone who's keeping a secret. Meanwhile Blue Diamond gives off the sense that's she's repressing something, she's hiding something she can't get over and is more to her own devices. In That Will Be All when the two of them talk this is especially evident, she's been grieving over Pink Diamond for thousands of years and cherishes anything that was Pink Diamond. Yellow Diamond tells her to destroy all the bubbled gems who rebelled against her, but Blue won't because, "they were hers." She won't let anything go. I'll get back to this point in the next bit.
PIECE OF EVIDENCE 6: In The Trial all these points come into play. Blue Diamond wants to relish in what Rose Quartz has to say on her trial, but then there's evidence that Rose Quartz and Blue Diamond were close, close enough that Steven is still emotionally attached to her in some way. Yellow's attorney mentions that an illogical passion was what lead Rose Quartz to shatter Pink Diamond; TO THIS COMMENT, Yellow Diamond rolls her eyes, but Blue Diamond lowers hers. Despite an easy execution here, Blue Diamond pushes Rose Quartz to hear her thoughts. This on first watch is easily interpreted as Blue Diamond placing her anger and rage into Rose Quartz, but watch it all again with the thought process that Blue Diamond shattered Pink and Blue Diamond knows that she's guilty and Rose Quartz may very well know she's guilty. The whole scene still makes a lot of sense, in fact it maybe even makes more sense. Watch The Trial with the thought process and you begin to notice Blue Diamond's little ticks and emotional moments play perfectly into someone who's guilty and repressing the guilt.
It's just my theory, but I think there's a LOT more evidence to support Blue Diamond having done it than Yellow at this point. And you know how much these writers love their foreshadowing. Yellow Diamond may be quick to anger, and that can make her look guilty, but I think there's no evidence Yellow did it outside of her anger at the end of the Trial. Meanwhile, there's a lot that can be stacked up against Blue Diamond, and Blue Diamond having some relation with Rose Quartz.
I know the obvious culprit is Yellow Diamond, and it could be White Diamond because we know very little about her, or hell you could argue it was some conspiracy and Pink Diamond wanted it, but I honestly think Blue Diamond did it. I would even say it's been subtly foreshadowed since Season 2 of the show.
PIECE OF EVIDENCE ONE: In The Answer, we see that Blue Diamond was on Earth. We also see in the crowds the gems present are all blue/pink colored. It's also established that Blue Diamond was establishing a colony on Earth in this episode (that's why Pearl arrives to stop Blue Diamond's colonization), there is no mention of Yellow Diamond having any involvement with Earth and moreso it seems Yellow Diamond just wants to get rid of the planet. But it's confirmed both Pink and Blue diamond were on Earth, and Blue Diamond was trying to establish a colony on Earth.
(side note: It's easy to feel empathetic for Blue Diamond, but you must remember she's not a good person. There's a reason Garnet fears her, and the Blue-based gems almost seem particularly troubled.)
PIECE OF EVIDENCE 2: Steven, who is and isn't Rose Quartz, is shown to have a particularly strong connection to Blue Diamond in Steven's Dream. On the opposite side of the planet he see's from Blue Diamond's perspective in his dreams and begins to cry her tears. The only people Steven see's the dreams of are those he is close to, yet he doesn't know Blue Diamond, implying that Rose Quartz was close to Blue Diamond. Blue Diamond can create an aura that makes all nearby people cry, but this happens within a radius that wouldn't spread to the other side of a planet, and specifically only Steven is crying when she's on Earth and not the other Gems. Through this a connection between Rose Quartz and Blue Diamond can be established. And it's notable Steven only responds in this way to Blue Diamond, and responds to it when no one else is responding to it.
PIECE OF EVIDENCE 3: In the same episode, Steven's Dream, the first line we hear Diamond muttering to herself in front of Pink's vehicle is how she's sorry, so sorry. She says she thinks this is still Pink's planet. Greg asks if Blue Diamond was close with Pink, to which there's a zoom-in on Blue Diamond's face when she says, "Very." As we establish in The Trial, the person who shattered Pink Diamond was someone very close to her.
PIECE OF EVIDENCE 4: Blue Diamond seems especially interested in preserving Pink Diamond's legacy. Something that doesn't make sense here: Pink Diamond was a threat to humanity and the Crystal Gems were fighting her for protection of Earth, Pink Diamond wasn't on the Crystal Gems side. So why does Blue Diamond have such an invested interest in protecting humanity and preserving it (and even keeping Pink's bubbled gems, who Pink would've probably gotten around to shattering anyways as they were rebels to her?) and what Pink Diamond stood for? Could there be a chance Blue Diamond believed in what Pink Diamond had initially stood for but not where her actions were headed so she chose to preserve Pink's legacy?
PIECE OF EVIDENCE 5: Yellow Diamond is very blunt, she is presented as being very straight-forward. She will get what she wants no matter the means and doesn't seem to hide her feelings or intent, she will publicly destroy her enemies and make a show of it, not keep it in the shadows. She won't let herself fret over things, she is malicious but she's certainly not presented as someone who's keeping a secret. Meanwhile Blue Diamond gives off the sense that's she's repressing something, she's hiding something she can't get over and is more to her own devices. In That Will Be All when the two of them talk this is especially evident, she's been grieving over Pink Diamond for thousands of years and cherishes anything that was Pink Diamond. Yellow Diamond tells her to destroy all the bubbled gems who rebelled against her, but Blue won't because, "they were hers." She won't let anything go. I'll get back to this point in the next bit.
PIECE OF EVIDENCE 6: In The Trial all these points come into play. Blue Diamond wants to relish in what Rose Quartz has to say on her trial, but then there's evidence that Rose Quartz and Blue Diamond were close, close enough that Steven is still emotionally attached to her in some way. Yellow's attorney mentions that an illogical passion was what lead Rose Quartz to shatter Pink Diamond; TO THIS COMMENT, Yellow Diamond rolls her eyes, but Blue Diamond lowers hers. Despite an easy execution here, Blue Diamond pushes Rose Quartz to hear her thoughts. This on first watch is easily interpreted as Blue Diamond placing her anger and rage into Rose Quartz, but watch it all again with the thought process that Blue Diamond shattered Pink and Blue Diamond knows that she's guilty and Rose Quartz may very well know she's guilty. The whole scene still makes a lot of sense, in fact it maybe even makes more sense. Watch The Trial with the thought process and you begin to notice Blue Diamond's little ticks and emotional moments play perfectly into someone who's guilty and repressing the guilt.
It's just my theory, but I think there's a LOT more evidence to support Blue Diamond having done it than Yellow at this point. And you know how much these writers love their foreshadowing. Yellow Diamond may be quick to anger, and that can make her look guilty, but I think there's no evidence Yellow did it outside of her anger at the end of the Trial. Meanwhile, there's a lot that can be stacked up against Blue Diamond, and Blue Diamond having some relation with Rose Quartz.