Plot Holes and Spelling Errors

Admittedly the starting point is that Kris is assigned the guitarist role during Lightners Live. The Soul comes off as skilled at guitar (we're able to play music with only two inputs) compared to the piano (sixteen inputs). And Dess is strongly associated with the guitar.

Kris' relationship with the Soul is odd. Granted, yeah, if an extradimensional creature puppeted me around I'd be annoyed too, but Kris also knows more than we do at the moment. Assuming Kris is a normal human, we're not their original Soul. Everyone else describes Kris and Dess as friends, but there's an undercurrent of sibling-esque violence whenever it comes up.

Interestingly, there's no canon dialogue that confirms she's a monster. Deltarune sometimes goes out of its way to avoid the topic, as if it's a sensitive subject for Kris. Of course, there's no dialogue that confirms she's human either, but most dialogue in the game about Dess assumes Kris knows who Dess is, so why would they describe her to them?

Dess (or a version of her) is canon to Undertale, but the monsters in that game are generally bad at recognizing humans. And the only description of her and Noelle in that game I can find only refers to Noelle as having antlers. Sans uses the phrase "the antlered girl and her big sis," implying Dess didn't have antlers when they met. It could just be that Sans didn't really know her that well (it's Sans, the man has his own secrets) but it's a weird detail.

Now for this to be true, that same scene would have to imply the King wouldn't recognize a human. Which is patently false - Asgore recognizes what Frisk is on sight. ...or does he? What if Asgore recognizes a human Soul, but not the body? Kris proves that a human can walk around without a Soul. Maybe that's what Dess' body did in Undertale, started shambling around like a zombie, got adopted by the Undertale Holidays. Maybe a ghost possessed her and is acting as a replacement Soul? Maybe that's why Undertale monsters assume Frisk is a monster?

To date, the only songs with lyrics are "Don't Forget," "Big Shot," "Raise Up Your Bat," "Flower Man," and "Cutie Mew Mew Magic."

Of these songs, Raise Up Your Bat and Flower Man don't have spoken vocals. The player has to read them.

The singer of Don't Forget is ambiguous. I have reasons to believe it's Dess but for the sake of clarity let's just accept it's not known at this time.

Big Shot is Spamton's battle theme and, implicitly, is his voice. I'll come back to this point but for now keep in mind Spampton has a very unusual cadence.

Cutie Mew Mew Magic feat. Hatsune Miku, is a facsimile of human speech.

Tenna's introduction is voiced, and his chapter has some voice lines. Even his voice pips have more of a spoken word cadence to them. And since his whole deal is copying tv broadcast ideas, why wouldn't his speech patterns also have copied what's on the air? And if that's the case, knowing he has connections to Spamton, that could even explain why Spamton sounds like that - they're both capable of human sounds but it manifests differently in the two of them

Flowery is explicitly attempting to come off as human. And he's apparently good enough that Susie assumes he's human at first. But what about his appearance would make Susie think that a man she's never seen before, in the Dark World, is human? Well, what if it's because his intro is also voiced, and he has the voice clips? It's part of his humansona effort - it doesn't hold up to scrutiny (it's tinny and jittery, and lines start to make less sense in context), but it's a weird detail if it's completely unnecessary to begin with

So what does that mean when we never hear or see Kris' voice? Noelle has actually described what they sound like, that under the Soul's influence they sound off - "as if it's on speaker." She obviously means that there's a difference between their normal speech patterns and the controlled one, but why compared to speakers? Well, listen to Flowery's voice lines, Tenna's broadcast, Spamton's (admittedly hard to hear) lyrics, and Hatsune Miku's artificial voice. They all have an artificial, echoey property to them.

And we know it's not a technical limit. Don't Forget has none of that artificial twist the other voice clips have. The song likely has bigger significance, but I think it's in Chapter 1 because it needs to put in the back if the players head what a voice sounds like, so we can recognize at least subconsciously what a fake human sounds like.

Uh

Can the spider lady come back?