Quantum Knight Theory

The observer theory in quantum mechanics states that quantum systems exist in multiple states at once and the process of observing or interacting with it forces it into a single definite state.

The knight can be multiple people but has to be one specific one by the end of the story.

The prophecy is like a quantum truth. It is defined as a string of phrases and images that can have multiple meanings. The identities of who the three hero's are is in question throughout the story. The girl could mean Susie, Noelle, or recently princess Ralsei. The prince of the dark could be Ralsei or Lancer. The first hero, with human soul and parts could even mean a few things. It could refer to Kris or, because the soul can leave and the "parts" being vague, someone made of human parts like at the beginning. It could also be as foreshadowed, someone with Kris's hand.

The pattern described plays out in the the different routes players are able to take. The normal route, weird route, and sword route. This assumes these three routes all follow the prophecy.

There is a lot of discussion of who the knight could be. I don't know who it is either, but I wanted to present a possibility. There could be one knight with multiple potential identities throughout most of the story with evidence strong and weak for who it could be. Based on the choices made by players the observed identity of the knight would be different depending on which route is taken. I imagine the Knight could be anyone with enough broken dreams by the loss of Dess to wear a suite of armor covered in shadow crystal. With main suspects being Carol, Rudy... and Papyrus?