Obviously some people believed it beforehand (the Ralsei-like scene was sometimes used as Transei evidence even back then), but the general consensus, even among people who believed certain unconfirmed characters (e.g. Noelle) would be canonically trans, was that Ralsei was cis male that happened to be feminine. I saw multiple "Deltarune Characters ranked by transness" things during the Chapter 2 era, and Ralsei was usually towards the bottom, usually considered "GNC but not trans."

No, Chapter 1 era stuff like that Treesicle "Ralsei is a woman" video doesn't count. That idea was that Ralsei was a cis woman that the characters assumed was male. A lot of people who believed that quit after Chapter 2, and I don't think any of them even considered the possibility of Transei. Honestly, that actually was an example of people thinking a feminine character had to be female.

It was Chapter 3 and 4 (and now 5) expanding on Ralsei's character arc that caused Transei to become popular. Beforehand, most people didn't quite understand what Ralsei's arc was, usually tying it only into the meta aspects of Deltarune. The new chapters make it clear that Ralsei's arc has also to do with them not liking the assigned fate and (implicitly gendered) role they actively want to change despite (seemingly) being raised their "entire life" to be this role and believe it is unchangeable. Ralsei could be a rather masculine character, and that would still a very trans story.

Imagine an artificial heart that is transplanted into someone to replace their old heart; this artificial heart happens to connects to their brain. The heart functions as a regular heart for the person it's inside, allowing their body to function normally; without it they would die as they have no other heart. However, the connection to their brain allows someone else to mind control them. That's kinda what (I think) the Player's Soul is. It's not the Soul of the Player; it is a Soul that is theirs and they use as a controller of sorts.

Oh, as an aside – back in the Chapter 2 era – some people (semi-jokingly) suggested that we have three Souls and that's what allows us to have multiple save files (as having six souls allowed Flowey to have six save files back in Undertale). Some have suggested (and I do believe this at least) that each Save File is its own slightly different timeline due to some minor things changing on each file.

That said, if she did, I don't think she'd be all cold and scheming if he really is dying as some think. What I'd expect is her feeling genuine grief and some guilt. I would expect her to shift the blame ("It's Susie's/Kris's fault for making this necessary"), but that'd just be a way to cope with and hide from her own guilt. (one idea I had for the "Carol made the old Dark World" theory is that she's also be doing this with Dess's disappearance and Kris, by the way)

You know, I spent a decent amount of time trying to make up a fake name for Temmie, but then I remembered she already exists in-universe, so it'd more redundant than anything. Also, I just love the idea that she only one whose in-universe version goes by her irl name.

Anyways, one idea in that theory was that Shadow Mantle from the Mantle game wasn't the same Shadow Mantle Seam had, and I still thinks that's possible. The idea was that the Shadow Mantle Seam had was in-universe merchandise based on the Mantle game itself. Note that the Shadow Mantle seemingly confirms that things from video games can eventually grow to full size once out of the Dark World.

The theory as whole would've involved saying that ERAM, FRIEND, and Ralsei were all the same kind of special Darkner: in-universe video game characters. I think I made it with Device Theory in mind. Much like HERO_SWORD briefly did, they got a Lightner's Soul that allowed them to leave their game and potentially traverse between Dark Worlds.

My idea was FRIEND got Dess's Soul when she disappeared. I was never sure how that happened, but Chapter 5's implication that a Dark World was involved in Dess's disappearance does make it possible. I'm not actually certain what my idea was for ERAM specifically beyond "they're familiar with Kris because Kris played the Mantle game a lot, also Eram themself was always part of the Mantle game." I originally made this theory with the idea that ERAM and FRIEND were separate, but I'm actually more of a "ERAM is FRIEND" believer nowadays, and this whole idea kinda works better with it in mind. Maybe they're the same character in two different games. Also, FRIEND was from Cat Petters the RPG as evidenced by Noelle's blogs. I was not the first to think that, but it bares stating that this theory was made under that idea.

Ralsei being like them was the idea I had the least confidence in yet the most to talk about. It was more of a suggestion than a real theory, but one I found bizarrely interesting. It was a variant on the "Ralsei has Kris's real Soul" theory where Ralsei was a video game character that was given Kris's Soul. I had two ideas for where Ralsei came from. Either he was also from Mantle (meaning Ralsei is HERO_SCARF; this idea could maybe also work with any other Dragon Blazers game), or Ralsei was from the video game Asriel was making.

For those not aware, Asriel having an unfinished video game may be based on Toby Fox's real life older brothers making video games that were (for the most part) never finished. His eldest brother had a game with a character based on Toby in it named "Green Mage Toby." Ralsei may be a combination of both that character and the protagonist "Ralse." With that (and my general suspicion that Toby based portions of Deltarune on his own life) in mind, my theory was that Ralsei was an in-universe video game character that Asriel made based on Kris, possibly with input by Kris.

Of course, there are holes in this idea.

Yes, Ralsei's ability to traverse between Dark Worlds could be explained by him having Kris's Soul, but Ralsei could only have gotten Kris's Soul at the beginning of the game when we possessed them. If Ralsei was from the Mantle game or Asriel's game, how would he get to the supply closet from there? One idea I had was that Kris got a physical copy of whatever game Ralsei was from in the supply closet (if it was Asriel's game, it was presumably some kind of debug build). Presumably, the school also had a console there, which isn't that unreasonable; I can easily see the school having game consoles for playing educational games with the class.

But the fact that Ralsei did anything in the Castle Dark Town before we got there still doesn't mesh well with the idea that Ralsei is from a video game, as he would've only left it after the Chapter 1 started. Granted, the only things we know he likely did before we got to Castle Town was set-up the training dummy and make the manual, neither of which would've required much time. In fact, he could've done that within the video game he is from, as the Shadow Mantle (regardless of its true origin) does show items can be taken out of the Dark World.

And then there's the big one that plagued any "Ralsei is based on Kris" theory: Ralsei and Kris's genders. It would be weird if Asriel based Ralsei on Kris and made Ralsei male. Although, if Transei ends up being real, this may not actually be an issue after all. It would make some sense if Asriel made a character based on Kris and had the character go through a journey of discovering their gender identity over the course of the game. I know I wouldn't mind my siblings doing that with me. Given the game was unfinished, though, Asriel maybe didn't finish writing Ralsei's trans journey.

That said, there is one major issue with this entire concept. How did Ralsei and FRIEND continue to control themselves after leaving their game if HERO_SWORD was entirely under our control and vaporized the moment Susie pull the plug on its controller? My best guess was that neither were playable characters in the games they were from (would kinda destroy the idea that Ralsei is from Mantle, but that's fine), so that limitation wouldn't apply.

So, right before posting this, I decided to check if anyone else had this idea, and someone named Nighthawk had a similar idea but way more sensible. It's worth watching,

I decided to go and check, and they (while wrong about Asgore saying it "outright") may be right about that. Asgore's wording is a little vague, but – going of his eyes and arm – he can only be talking about his arm hair. You'd think this would be referring to it being different colors in the Light World and Chapter 5's Dark World, except Asgore's arm hair is the exact same color in both: E4BA00

One of three possibilities:

One, Asgore is a tetrachromat that can distinguish shades of yellow better than most people. I guess I can't disprove that, but that seems like a stretch.

Two, this is a genuine, out-of-universe mistake. Admittedly, quite possible, but I'm not sure how it would happen. It'd probably be easier to select all the pixels with the same color and recolor them all than it would be to only recolor the hair on his head and face, especially as it's not continuous. And it'd have to be a consistent mistake given every sprite of Asgore in the Dark World has it.

Three, Asgore doesn't mean it's different from the Light World, but that it's different from the last Dark World he was in, like Susie's Dark World. His vague wording may be an intentional misdirect.

This could be potential proof of the old Dark World being made by a different than the Knight. That said, I feel the need to point out that's not necessarily the case, as it seems that the different lighting is the result of different wills and not just different people. Under (for example) Dess Knight, Dess could've made the fountain before becoming the Knight, so her will changed and that's why the lighting is different.

Ralsei does seem to believe Plantners don't count as Darkners, so that's why I don't believe in that theory. If he was a Plantner, then I don't think he'd call himself a Darkner. I'm not sure exactly what he is, but I don't think Ralsei was lying about being a Darkner, just not being specific about the whole truth.

The Tenna Flashback shows everyone before Dess disappeared. Kris is shorter, but not by a lot. Yes, young Kris is sitting this scene, but you can generally assume the length of one's legs from their torso. I'm probably underestimating their height by assuming they're the same length, as legs tend to longer than torsos.

If we're generous to Kris, they grew two inches. If present Kris is present Noelle's age, 16-years-old, that would mean this flashback had to have been when they were about 12 at youngest and 14 at oldest. That would mean Dess's disappearance happened two to four years ago. I prefer to say it happened about three years ago and Kris was around 13-year-old at the time as that's in the middle.

I've explained elsewhere why the How to Draw Dragons book doesn't prove anything regarding when Dess disappeared, and I think people assume Noelle and Berdly were younger than they likely were in the spelling bee. Berdly doesn't specify any age in his dialogue, and – even in real life – you can participate in those at age 14. While Noelle does seem significantly shorter than her present self, I'd point out that Noelle is a fictional deer monster, so – unlike Kris – we can't really use her height as reference for how much time has passed.

By the way, Berdly is proof that real human development can't be applied to monsters if that bird teacher from the anniversary stream is his mother. Anyone who has been teenager can tell you that human teenagers tend to be the close to the same height as their mom (me and my siblings were as tall or taller than our mom when we were thirteen), but Berdly is significantly shorter than his mom despite being a high schooler.

This can also double as a defense of the Fill-in-the-Blanks Theory, by the way

I have to say up front that this only really works if you accept the idea that the accompanying visuals in Chapter 4 were just depicting the current iteration of the prophecy and aren't actually part of the prophecy itself. If you don't accept that premise, I understand completely. Just know that part of this idea is that those visuals aren't part of the prophecy proper. The in-universe reasoning could be that Chapter 4 Dark Worlds were made by members of the current iteration (the current Knight and Susie), so their Dark Worlds would depict the prophecy with visuals of their iteration.

I want to restate: you don't have to agree with that reasoning. If you don't agree with it and dismiss everything else here because of that, I understand.

Anyways, let's start with the big one: Jockington.

Seems pretty explicit, right? Well, I have question for you: have you ever met someone named Peter? Or Mathew? Mary? Abraham? Noah? Abel? Or just any name from the bible in general? In some cultures, Jesus and Moses are common names. If a biblical character was named Jockington, you'd see that name in real life (you might in a few decades anyways when Deltarune fans are old enough to have kids en masse). My point is that if the Prophecy mentions the name Jockington, wouldn't be realistic if tons of people were named Jockington? And how many of them have likely grown beards?

Moving on, there are others people say are specific to characters we know, but are they actually specific or do we think they are because we know what they're referring to?

In the case of "The Flower Man" we, the real life audience with more information than characters, got it wrong even with the visual partly because the wording is that vague. And again, if you dismiss the visuals (which, again, I understand if you don't want to do that), these lines are more vague than you think. All that's required for Lancer's panel is some pointy-headed person saying "Toothpaste Boy." "The Queen Chariot" is already twisting the definition of "Chariot" to apply the Queen we know, there's a over a dozen definitions of Screen, and that last one (which is unused, by the way, if you don't recognize it; if you want, you can actually dismiss it on those merits, but I understand if you don't) only requires an axe connected to a Tortoise's hammer. Maybe it was even the same one, Gerson could've been alive for the previous iteration. In fact, under Dess Knight, maybe Old Man is partially based on Dess's memories of Gerson in the previous iteration?

I don't see people bring this one up, but it's one I thought of, so for thoroughness I want to mention it. The Prophecy contains the solution to the piano puzzles of Chapter 4.

I personally think this can easily dismissed if previous iterations also had piano puzzles. In fact this doesn't require pianos at all, just some form of musical puzzles. Remember, Dess was guitar player, if these were guitar puzzles she could've solve it.

Next, some people say that the prophecy mentions the SOUL and therefore the Player, and we certainly weren't there for the previous iterations.

There are two ways to approach this. The first and more direct way is that this line is vague enough that it doesn't actually need to refer to anything like the player. It just says the cage has a human soul, that's it. It could refer to Kris's situation or a human under normal circumstance. And while that's definitely a fair counter argument, might I suggest something else?

The prophecy does mention the Cage getting possessed by something, but it doesn't need to refer to us specifically.

How does this sound: "The Cage shall act as the will of a being from another world." What if previous iterations had different kinds of otherworldly beings, and this time around it happened to be us? Different humans (or human-like beings, see the vessel) throughout history have acted as the Cage for otherworldly beings throughout history. Watch, the earliest Cage in history was actually possessed by Cthulhu or something. This idea admittedly works only under Cycle Theory specifically, but I do think it could work.

In fact, under the idea that Kris was part of previous iteration, I suspect they were possessed by someone else.

(yes, I am using this as an excuse to share an idea I had for Cycle Theory, sorry)

You've probably already seen evidence that Kris was possessed before the start of the game (e.g. the Bird Cage), but I usually dismissed that on the grounds of "Kris seemed to be working with the Knight (or someone who knows something about this whole mess) beforehand, so Kris could've prepared for this with their help." However, Chapter 5 does have one notable bit of evidence that makes me think it's more viable now.

Many have used the summoning Catti mentioned as potential proof of Summoning Theory, the idea that Kris (intentionally or otherwise) summoned the player with Catti. I'm not going to dismiss that idea, because I do think that's actually quite probable now, but I want to bring up one specific part: she said the summoning happened "way back then."

I want to restate this doesn't discount the idea that Kris unintentionally summoned the player specifically. It could something like "If you mess up the summoning, something bad will happen years from now," but what if the consequences didn't happen years later but very soon? What if this is how Kris became the Cage the first time around? Presumably, they were possessed by a different entity, unless those Chapter 0 theories end up being true (which I actually do doubt; I'm a "that was just a placeholder" believer). This time around, they ended up possessed by us because something went wrong with the Vessel creation, so we got put in Kris as the best runner-up.

Back on topic, there is one other specific thing that could be used as a counter to the idea that the Prophecy has happened before. I say "could be" because this is another thing I realized myself but haven't seen yet. It's a pretty big one for Cycle Theory specifically: this line.

If the Prophecy mentions Hyperlink Blocked, that could only be referring to Spamton. Maybe it could work if someone else said that, but this feels way more than that. Maybe Dess's iteration went into an internet Dark World, but my Cycle Theory would be hit pretty hard by this idea. I doubt even in Deltarune's universe the internet existed for centuries. I'll admit it, if the Prophecy does mention Hyperlink Blocked, then this would disprove my Cycle Theory.

But I think it's possible it doesn't.

Here's the thing: we don't see what part of the prophecy this refers to. Hear me out: this NPC is also speculating on the accompanying visuals, not just the words of the prophecy itself. Let me remind you that this chapter also has a bit where Darkner NPCs speculate on statues of each other without understanding the actual truth of the matter. What if this NPC saw a visual of Spamton saying "Hyperlink Blocked" and assumed it was part of prophecy.

I'll say it myself: this is a stretch. No other panel has wording in its accompanying visual. But as we don't what this actually refers to, it is possible this NPC isn't actually referring to the words of the prophecy.

I guess you could also argue they aren't even referring to anything related to the prophecy at all, though I'm not sure what else that would be.

Anyways, that's my best attempt to defend the idea that prophecy happened before (we'll call this Previous Prophecy Theory, of which Cycle Theory is a variant on). You may not be convinced, and I would understand. I just want to be clear that it is possible that the prophecy is not specific as some think.

Oh, also regarding the Prince Asriel theory, I want to bring some things up. I'm saying this separately from the above, since – while Asriel is the main idea I have for who the previous Prince of the Dark could've been – I am open to the idea that it could be someone else (maybe some random Darkner we don't know).

The only line of the prophecy regarding the Prince (that we have seen, at least) is this:

Catty's sermon is obviously a joke, but this could also be foreshadowing an actual truth about the prophecy: the heroes could have been anyone who fit the description of the heroes.

That is to say that the heroes aren't chosen from birth or anything, they become the heroes of the prophecy when the events of the prophecy begin. Susie only became the Girl in the prophecy when she fell into the Castle Town Dark World. Hypothetically, if Noelle went with Kris at the beginning of the game instead of Susie, she could've been the Girl instead with no complication. That said, I suspect the prophecy makes it clear the roles are consistently filled by the same people throughout, so you can't swap someone else in partway through as some have suggested. For example, while they both could've been the prince, you can't replace Ralsei with Lancer at this point, as Ralsei has already become the prince of the prophecy.

On that note, I think Ralsei may genuinely believe he was always meant to be the prince, but he thinks that not because the prophecy says "Ralsei is the prince" but because he was raised from "birth" to become the prince. Alternatively, Ralsei is aware of the "fill in the blanks" nature of the prophecy's roles, but hasn't mentioned it yet as it wouldn't actually affect anything. I've said this before, but I think it's worth restating here that I suspect Carol was raising Noelle to be the Girl, and her disdain for Susie is at least partially motivated by her "stealing" the role.

I've actually had this idea since Chapter 4, mainly when speculating on possible reasons for Carol's personal disdain for Susie, but I don't think I ever voiced it until now. I guess I've already implied this idea back with my Cycle theory (and that theory does necessitate this being true), but I want to clear that this can function on its own even divorced from the idea of the prophecy being a cycle. So even if that's wrong, I'm willing to bet this idea is right. That said, I will admit I'm not sure what what meaningful implications this idea could have for the plot if it's true unless it's part of a bigger twist. (such as my aforementioned Cycle Theory or Truman Show Theory) I think it's a possibility we should keep in mind, at least.

One idea I have, though, is that Carol and Gaster may have had their own conflicting ideas of how the prophecy should manifest. I'll admit, I don't have any evidence for thinking this, this is firmly wild speculation territory. I've said this before too in the Truman Show Theory (in fact, I've also had this specific idea since Chapter 4), but it bears repeating here as it is relevant to this idea. Gaster may have wanted the Vessel, Susie (I'm less certain on her specifically, but I'm willing to believe it), and Ralsei to be the Cage, the Girl, and the Prince respectively, but something went wrong with the Vessel and Gaster compromised by having Kris be the Cage instead.

Carol may have wanted Kris, her daughter (at first Dess, then Noelle after whatever happened with Dess), and potentially Asriel to the Cage, the Girl, and the Prince respectively. I'm quite uncertain on Asriel counting for the Prince, but you could make an argument for it in an admittedly very roundabout way. Asgore says he and Kris are royalty because of the Festival King and Queen stuff, and Asriel would be the son of the police chief, so he could metaphorically count as a prince; it's very dubious, but it could work. Also, Asriel likely has horns, and Catty claims the prophecy mentions one of Heroes having horns at some point.

Maybe Carol was hoping the Prophecy would happen while Asriel was at Hometown, but it happened either too early or too late. Alternatively, Carol could've been okay with Ralsei being the prince from the start. Regardless, her plans for Noelle was unknowingly sabotaged by Alphys sending Susie and Kris to the closet together. I want to restate, I have no firm evidence or reason to think this. This is just me rambling about my rampant speculation and I want to share it.

Sub-theory, if Dess is the current knight, maybe the "final tragedy" is that a member of the trio has to become the knight for the next cycle. Admittedly, Ralsei's reaction would be a bit odd if that was part of the prophecy (if the Prophecy said a member of the trio has to become next Knight, Ralsei wouldn't be surprised by the Knight existing years ago), but maybe the prophecy is vague on that detail. For example, maybe the prophecy says "the Knight must take a hero's life away" and it sounds likes they have to let the Knight kill them, but it really means sacrificing the life they would've had to being the knight (the "Knight" referred to here isn't the person, it's the role). Maybe the Black Knife was the weapon of all the Knights throughout history. Nonzero chance Kris being knighted in Chapter 3 is foreshadowing them becoming the next knight.

Under this idea, the panels in Chapter 4 were only depicting the current iteration. I've suggested before that Carol could've went through something analogous to the Weird Route in her adolescence, but that could be a bit more literal under this idea if Carol was part of a previous iteration. This could also fit in my Truman Show theory, as the prophecy could've happened within Hometown multiple times for a long time. Honestly, that could be the case even without my "Hometown is a Seahaven Island-like environment designed for the prophecy" idea.