Calling it now:

Dess is the Knight, she is calling out to Kris for help to save herself and Noelle.

Ralsei is Kris’s toy horns, but Asriel did magic on them well before the game started.

Kris is a zombie. They died before the game started due to a “harmless” prank gone wrong.

Asriel and Dess worked together to use magic to bring them back “to life”. In the process, Dess was trapped in the darkness inside of Kris.

Our intrusion as a “soul” is also due to occult practices in-world.

Kris is their own person with their own interests and wishes, but they are seldom free to express it through any means other than being the narrator. Most of their energy is spent through the night with [The Knight’s] activity, and most of their energy during the evening is spent through [The Soul]’s activity.

Kris is tired of being in this in-between alive state. They want the freedom to make their own choices without being suppressed by others. And while their reaction to Spamton suggests their fear of the other option for freedom, they are probably not as negative on that potential outcome as we might assume.