My silly theory about the soul in Deltarune and Undertale
My theory is that the soul in Deltarune and Undertale is the same one, and it is Chara’s soul. This theory consists of other theories, so don’t take everything too seriously.
I want to start with what I believe: Kris is not a parallel version of Chara.
First, Kris is afraid of or feels disgust toward humans. This is important. You can see it in the scene where they open a book that shows humans and immediately close it, clearly not wanting to look at them.
And Chara hates humans. They were planning to destroy all humans — this can be understood by looking at the cassette recordings in the lab.
Second, as far as I remember, Toby Fox has never changed the names of characters that appeared in Undertale. And what is the true name in Undertale? Chara. Chara is the first child who fell into the Underground and was adopted by the Dreemurrs.
Third, this will be my assumption, because the relationship between Kris and Asriel has not yet been fully revealed. But I assume they were inseparable.
But what were the relationships between Chara and Asriel like? Again, we return to the tapes. From their recorded conversations, we can understand that Chara manipulated Asriel, brought him to tears, forcing him to agree with their plan. It can also be said that Chara killed Asriel. Humans did not kill Asriel — it was Chara.
When they were dying, Asriel crossed the barrier. Humans thought that he had killed a child and started attacking him. But then the recording says that Asriel returned, fell, and died already in the Underground. And Chara finished him off, which is why Asriel died in the Underground and not on the surface.
Alright, I’ll finish this part here and move on to the next one.
Chara. Chara has a Determination soul. A Determination soul always comes back, which means Chara is not dead. But where are they? One might think they are with Asgore, because he has a coffin with their name on it. But Chara is not there. Because if Chara were with Asgore, he would already have all the souls. Therefore, he does not have Chara.
This is where the theory I rely on begins. Gaster, our beloved green friend, somehow unexpectedly, judging by the records, found a source of Determination — more precisely, a body with a human soul. As I wrote earlier, Chara is not dead but is in a state similar to sleep or a coma. Because of this, Gaster was able to take them into his laboratory and extract Determination that way.
How did Gaster die? And did he even die, or did he simply fall into the files or the program code? But I will tell the theory I saw from one YouTuber. I’ll say right away: this has nothing to do with the CORE.
Gaster was experimenting with monster corpses and Determination. Realizing that the experiment was interesting but not very useful, he decided to return Chara back to Asgore. But Gaster, who had never held anything heavier than a pen, tried to pick up Chara — and together with them fell into the machine for extracting the soul. That is why Gaster did not melt as he might have in the CORE, but instead was split apart.
And Chara used their ability to be reborn. That is how Frisk appeared. But Frisk, essentially, does not exist — they are only the reincarnation of Chara. And Chara in the genocide ending simply transform into their true form. I think this can explain the red eyes at the end of the pacifist ending after genocide.
In short, it turns out that we, the player, are playing as Chara.
And I like the theory that the comments that appear when interacting with objects are Chara’s words. But I’ll say right away: Chara does not force us, the players, to play the way they want.
Now we need to think about how Chara’s soul got into Deltarune. Now there will only be theories on top of theories, connected with my guesses.
My assumption is this: there is no canonical ending in Undertale. So I decided to assume which endings could at least slightly connect with Deltarune.
In Undertale there is a mention of a legend that also exists in Deltarune. More precisely, a symbol that appears in both games: a circle with wings — the angel — and the triangles are monsters. And it is said that the angel wants to free the monsters. And the most important thing — this angel has been on the surface.
And who has been on the surface?
The player? No, we only see the surface at the end.
Chara? Yes. Because they were the first child who fell into the Underground.
This legend was told by Gerson on the neutral route. And the word “free” is used there.
How can someone be freed? Logically, helping someone escape imprisonment — that is what we do on the pacifist route. But there is another path — killing, which in some sense can also be considered a kind of release. This happens on the genocide route.
Honestly, I don’t know why I decided to mention this, but let it be.
So: how could Chara’s soul have gotten into Deltarune?
Relying on the theory that Gaster might have created Deltarune, we can assume that he created this world after some neutral ending of Undertale. I think this because the soul remains in the Underground in those endings, and we learn the consequences of our actions.
In the genocide ending, Chara takes our soul.
In the pacifist ending, we are freed and see the surface.
So only the neutral endings remain.
I think that somehow Gaster managed to obtain the soul that remained in the Underground and used it to create Deltarune.
It is unknown whether Kris had a soul originally. But it is clear that they do not necessarily need one. Kris can calmly walk and do whatever they want when they separate the soul (the player) from their body.
But I want to assume that Chara might have helped us on the weird route (Snowgrave), because this route is very similar to genocide.
For example, the choice “proceed.” This already shows some kind of interference in the game itself and in the player’s choices.
Also, the way the player manipulates Noelle is similar to how Chara manipulated Asriel.
Another point perhaps the soul came from Undertale. This can be understood from one of the answers we can give to Sans, where we recognize him. But the problem is that Sans himself moved to this town quite recently. Which means it is the soul that recognizes Sans.
