>>534096325
More theory slop because the thread is about to die anyway and I'm bored.
The Soul is quite literally L(o)V(e). Level of violence.
There's outside forces that's making it unable to gain EXP (because you're not playing the real version of Deltarune). Defeating enemies forces them to flee instead of getting killed. (The sword (ability to kill) is missing)
Spamton lays it all out in the weird route.
[hyperlink blocked] is LV and he's using it as a pun for a suggestive joke that's he's self-censoring. He used to be a TV big shot after all.

Noelle is the only character in the entire game that can gain EXP through acts of LV with a loophole. "Noelle gets stronger" is deliberate. It's not "Noelle gets # amount of EXP." The "soul" within her is barely forming at this point, so she can only surmise it as "getting stronger".

In chapter 4. Originally when you equipped the engagement ring on her as an act of LV, the image of this act was shown as a rose falling apart within her, which is misleading- and Toby knew it. That's why the change leans towards it being violent. It's creating a soul through violence.
"Strengthened an imagery while while maintaining the scene's intended meaning."