So, now that it's finally been outright confirmed that Shadow Crystals are lost dreams, and people might actually listen when I talk about the theory, I thought I might go over some of the stuff about them that we'd already figured out, especially since I've seen a lot of people not really understanding what Seam meant, or the mechanics of the Shadow Crystal's creation. Even at this very moment, there are scores of people who still think the Knight is handing out Shadow Crystals like fucking Santa Claus.
And, while I'm here, I'd like to refine my old theory on the topic. A lot of this post will be me restating stuff I already said back in January when I originally posted my Shadow Crystal theory but slightly better.
Shadow Crystals appear with or on Darkners with a strong link to the broken dream of a Lightner. Spamton's crystal, for example, came from Mettaton's dream of having a new body. Seam tells us Spamton found the crystal inside the NEO body, which is the Dark World manifestation of the paint file that Mettaton drew his ideal body in. Because of his strong feelings about the drawing, and the broken dream attached to it, when the Dark Fountain was created, a shadow crystal was created inside it.
We know where Spamton, Mew Mew and Gerson's crystals came from almost for sure. Spamton's came from Mettaton's dream, manifesting in the NEO body. Pink's came from Maddy and her transgender dream, manifesting in the Mew Mew doll. Gerson's came from Alvin's dream of writing, manifesting in his father's dust.
The Knight and Jevil's crystals, I don't really know for certain.
It's highly probable the Knight's crystal came from themself, since they are a Lightner, but it's hard to say what their dream was. After this chapter, it's basically confirmed that the Knight is the "fallen star" from the peculiar book, so we can apply all the bitter tears lore to them here. That's all super cryptic though, so there isn't really any conclusions to draw from it.
Jevil's crystal we have even less information about. The only possibility I've been able to think of is that he took the Shadow Crystal from Seam, who might have been linked to Asriel's dream, given they appear on his desktop. But we are long overdue for a lore dump on the school, with Ralsei and the Grand Fountain being located there, so we might learn more about Jevil then.
The strange someone's identity
While certainly no one handing out Shadow Crystals, there is definitely a certain someone who is suspiciously linked to them. The "strange someone" who met with Jevil. The mysterious voice over the phone who made a deal with Spamton. Gerson's feeling of "someone want[ing him] to use [the shadow crystal]".
I, personally, am fully of the belief that this person is Friend. They're one of the only people known to be able to travel between dark worlds, and the "garbage noise" on the other side of the phone is a file called "mus_smile", from Entry 17, to which Friend is tangentially linked thanks to its status as part of the DEVICE. Whenever someone else picks up the phone, there's no one on the other side, and the phone in the Z-rank room is unplugged. Friend is known to inhabit machines, like the vending machine in the S-Rank room and the MANTLE game. Spamton's glasses are coloured after its eyes, they appear in Queen's basement near the second Shadow Crystal, and in the MANTLE Game, where we're hunting for the means to reach the third. Also they are pink and yellow and a cat. Like Pink. But uh. That last one isn't really evidence of anything. Anyway, it's also a neat explanation for their name, "Friend". Jevil's friend, Spamton's friend, your friend.
Wait but if they aren't handing out the crystals then what are they doing
Short answer: I have no idea.
But I have some thoughts, and it can't hurt to lay down the evidence.
Let's go over all the confirmed things Friend (I'm just going to say Friend from here. Even if you don't think it's them, I'd just get tired of writing "strange someone" over and over) has done.
First of all, they met with Jevil. They told him about the nature of the world, and he went of the rails. At some point, he acquired the Shadow Crystal, before being locked away by Seam. Jevil also displays future knowledge, which may have been given to him by Friend.
They talked with Spamton over the phone for a long time, and gave him advice that made him into a big shot (likely more future knowledge), until Spamton was about to sign his contract with Tenna, when Friend said something over the phone that scared him, before ending their support and ruining Spamton's life. Spamton began praying to the NEO body, hoping it would make him big again, so there might be a link there. Interestingly, they continued to talk to him over the phone at least until he was evicted from Queen's mansion. Then, of course, they show up to watch us in the basement.
In chapter 3, they give us the OddController, and appear in the MANTLE game. Watching us, and attacking us in the ERAM fight. (I've heard people suggest before that Friend is trying to help us in that fight by dropping heals, but it actually doesn't even drop heals unless you've died at least once. So definitely trying to make the fight harder, but the chance for heals goes up as you die, so maybe they're lenient?)
Personally, I think ERAM is Friend, so I'd add giving us the Shadow Mantle and provoking Kris into a fight to that list as well. They also probably appear in the vending machine, and smile at us, saying "Always at your humble service".
In chapter 4, all they do is pop up in a hallway, and give Gerson the feeling the someone wanted him to use the Shadow Crystal.
They do literally nothing in chapter 5 besides show up in a random corner and give us a whack.
It's hard to draw a motive from all this, especially all the Spamton and Jevil stuff. They have to have been playing the long game.
Based on Spamton's dialogue, particularly that one monologue about "[[Communion]] WITH [[Unintelligible Laughter]]", it seems like he and Jevil had similar deals with Friend, and possibly the Knight as well. He talks about surpassing Jevil, and is threatened(?) when he mentions the Knight.
The main question to be asking is, what did Friend get out of this deal? They made Spamton a big shot, gave Jevil forbidden knowledge, all that, but what did they ask for in return? It might be nothing. Maybe they did it for "free", and just had some hidden ulterior motive.
My only real working theory for their goal is that they're trying to test us somehow. Setting up strong bosses to guard the Shadow Crystals, encouraging Gerson to use his to fight us, and leading us to the Shadow Mantle to give us a chance against the Knight... But ERAM was pretty obviously doing that already. And it doesn't really explain why they would interact so heavily with Spamton and Jevil. Without knowing the terms of their deals, it might just be impossible to say.
Yeah that's about it really we still don't know that much about the shadow crystals
Yeah, I don't have a great explanation for why Friend's doing any of this shit. Honestly, this is still extremely similar to my original post. Pretty much the only development we got about the Shadow Crystals in chapter 5 was confirmation of everything I already knew. And, just like last time, I invite anyone reading to try and think of some possible motives for our strange someone. Maybe some Spamton lore experts out there will know what he was paying to be a big shot, idk. I didn't even read the Q&A or recheck the sweepstakes for info, might be something there.