#our vessel WAS literally destroyed after all. neither kris' or OUR choices matter

[the-acid-pear]

the more i think about kris the more my insanity increases tbh there's just so much nuance with not only them but also the player and their relationship and it's layes upon layers of them and i keep tryin to peel them off inside my brain and its going to turn me into a dc villain or something

[leonhaxor]

Hello, yes, welcome to a Deltarune Theory

So, we all know how Gaster was the royal scientist for King Dreemurr. Built his greatest creation, the CORE - which we know that is a massive power source - and that Gaster famously "fell into his creation." Most interpreters thin it's the CORE he fell into, but it's not exactly elaborated upon. We also know what whatever he fell into, he basically became a glitch in the system of UNDERTALE's reality.

Do we really know HOW his CORE works, though?

The CORE was Gaster's greatest creation. Which, as far as we ever knew, was an absolutely MASSIVE energy reactor that provided power to all of the Underground. These are the facts here. Judging by all the lava, it'd be safe to say the power source was geothermal in origin.

The thing is, as far as 'greatest creations' go, this seems a little bit... too mundane. Yes, it's massive. Yes, it looks like Shadow Moses and Hollow Bastion had a lovechild (the castle in KH1, not the variant with an actual town around it). Yes, the overworld theme there is a banger. But at the end of the day it's still a glorified power plant. To his credit, it's unknown how long it actually took him to make it, as well as the implied time period they were sealed away being at least around Medieval Times, if not further back.

But even then... what about the CORE could shatter Gaster's existence across time and space (assuming it was the creation at all)?

Monsters can die to a lot of the same things any other living being can die to. There might be certain allowances, based on what kind of monster they were. If the CORE was geothermal in nature, if a fire elemental was to fall into its workings... well, barring the "drop of water in an ocean" possibility, it's highly likely they'd survive intimate contact with such high levels of heat. A monster that may or may not be a skeleton, like Gaster is widely believed to be? Probably has a melting point.

With the heavy implications that his fall into the CORE spread his essence across time and space, and the specific attention to getting those details across... would a fall into a mere geothermal reactor, no matter how large, actually spread one's being across existence in such an anomalous manner? What would set it apart from dying in literally any other part of the Underground, where monsters turn to dust instead?

As we have seen in both UNDERTALE and deltarune, a Fall is an *incredibly important thing*. Chara/The First Human fell into the underground, arguably fucking up everyone as badly (if not more so) than the human wizards of old who trapped monsters in the Underground. The six human children that came after did the exact same thing, leaving only their SOULs and their gear behind for Asgore and Frisk, respectively, to use. Frisk... well, they too fell into the Underground, and gave us the means to interact with that world.

What do monsters call dying of old age in their culture? Falling down. You know who also did this by the time we're in Chapter 1 of deltarune? Gerson. There’s a book in the  The one person alive who knew what the delta rune was, and who has been getting an awful lot of mention for a dead turtle, but I'll get to that later. Note that there was a distinct difference in the way that it was described for Gaster - he “fell into his own creation,” but he did not “fall down.” Humpty Dumpty might have been pushed.

But the point is, Gaster's own fall is fascinating because like in the context of the human children's falls, his Fall marked a beginning of a story (most obviously, Alphys', but I'm not sure that's where it ends), and the context of an end (such as Gerson's fall in deltarune, and his posthumous reverence by the community that he was from, much like the Followers do).

...so, what exactly might be the cause for Gaster's non-existence, regarding the CORE itself? How exactly did any of that end up being relevant?

Let's talk about deltarune's story for a second.

Recall that the Knight has been referred to by Spade King in crimson text... which, if you recall, is rather similar in color to that of the human SOUL in Kris.

But what kind of creature could this Knight be, to fight the Spade King and instill such profound loyalty within this monarch? When he is so powerful, so cunning, so ruthless, as we see him in his boss battle (as well as indirectly, though his effect on the Darkners' Kingdom)? What if I told you... 

Ahem.

Jokes aside, we do have to consider what kind of monster this Knight would have to be, one with the power to create the Holy Fountains. One that we haven't actually seen onscreen, and have heard even less of than King. Except... we might actually have seen someone, or rather something, that DOES have ties with the Knight, or at least his ability to manipulate the Fountains.

Kris.

Or rather, their SOUL.

Or even more specifically... a SOUL that we simply control.

Let's walk back a bit from the stinger, and work our way from there.

Here's a picture from the final scene we have so far in the Dark World, specifically of the “fountain” that we encounter. 

If you are viewing this in-game, the pattern is constantly scrolling diagonally, along the same line but in different directions. If you pay attention to it, you'll see this strange symbol that looks like a chinese fingertrap with spades on the ends.

Now take a look at this picture from the vessel creation screen. It’s been taken from just before the other menu items appear, for maximum clarity. 

Note how, while there is a constant rippling effect from the center, not unlike water in a pool, we can clearly see that there is a shape being distorted.

One that bears a striking resemblance to that of the fountain itself.

Both times we see this pattern, texture, whatever you prefer calling it... there is a brief interval where we see it, before a *Red SOUL* is seen in the center of it. And, directly afterwards, we are shown a white light that encompasses the entire screen, before we are brought into the World of Light.

Curiously, in the earlier variant, the screen turns white from the center x-axis and outwards, where the second one turns white from the center y-axis and outwards. Not entirely sure of the significance of the differing choice in axis, but I think it has something to do with the context of each entry. The first is our entry into the game, or rather the prologue, while the latter is our entry into the epilogue.

I believe that the former is representative of the SOUL's entry into the CORE, while the latter is representative of it returning from the depths of the Dark World.

Yes, you read that right.

I believe that the entirety of this game take place inside the CORE.

Between the curious reactions to entering his name into either of the inputs, along with all of the references to sounds and words associated with him, most people think Gaster is the narrator in the opening sequence. Or Chara, according to @Squigglydigg's initial theories playing the game. But while that'd be interesting to explore, I'll have to go a third route for the moment, as I believe there is more evidence to back this idea up.

I might as well address the name input easter eggs before I go farther. Neither "Frisk" nor "Chara" happen to elicit any sort of unique response from the narrator whatsoever. If you name Gaster as the Vessel, the program soft resets. But if you name him as the Creator... it shuts down immediately, before you can truly enter the "R."

I believe that this narrator we are introduced to is actually a program designed by Gaster himself, made to oversee the CORE's operations.

If Gaster is named as the creator of this vessel, the program crashes. Note that this name is also used as that of the SAVE file's profile. As far as we know so far, the vessel's name is inconsequential. It's been hypothesized that this vessel will become relevant in later chapters, but it is unclear if and how it would actually be used.

My current thoughts as to what the creator has to do with this program... is that whoever is actually using the program is in some form of VR simulation. One that, as suggested by the cage at the end of the chapter, is meant to trap the player. I’ll get more into how it tries to do so in the next part of my hypothesis.

I haven’t forgotten about the "Chara" figure at the end of the chapter. I think this is actually a clue to the true identity of the Knight, or at least the World of Light's equivalent. Recall that the one in the Dark World is never seen, but is able to summon the Holy Fountains of Darkness. King, in his fight, has an odd hatred for Kris specifically, calling them the specific name of "Lightbringer" for the first and only time so far in the game. Picture the act of what the Knight *does*, bringing forth a fountain of shadows from the Earth. When Kris stands before that castle fountain, it erupts into light (and is presumably destroyed, but then again, we don’t actually see the aftermath of this action).

The Knight is implied to be obscenely powerful, in both conventional combat and enough to create dark fountains, enough to make King into a willing and eager servant. If we look back at UNDERTALE's genocide route, we see Flowey (who in terms of power and personality greatly resembles King) eagerly supporting "Chara" in their slaughtering of the Underground. And, by the time we have defeated Sans, we've made them into a truly unstoppable killing machine. Note how the Knight's colortext has a unique red and black gradient effect, representing their ties to the darkness while also bringing to mind the infamous red text that accompanied our player-made killer's thoughts. Thoughts laid out in simpler text rendering, but noticably brighter hue than that associated with the Knight.

Also recall the words of Seam the Shopkeeper, should you defeat Jevil. He heavily implies that Jevil is only a taste of what is to come, that later enemies will be even more powerful than that reality warping madman. In the world of UNDERTALE, what has proven more powerful than a human with high LV?

Apart from human error... not much comes to mind, honestly.

In the next part of my Game Theory(TM), I’ll be going over what I think Ralsei’s part to play in all of this really is, as well as what the CORE actually *does* to generate power for the Underground.