After spending some time looking at all the reddit and tumblr posts discussing papyrus knight, I've come to the question that I think finally gets my feelings across as to why Papyrus as the true candidate of the Knight would be a massive mistake on Toby's part.
That being, why should Papyrus even be the knight at all?
Like I said, I've come across tons of posts talking about why Papyrus could be the main antagonist of Deltarune.
And while I do think they can make some genuine good points as to how he could be the candidate, I never really see anyone talking about the necessity of his role being that in Deltarune, outside of the fact that he isn't really a character in Deltarune at all.
Which, as fair as that sounds, I think the idea of forcing Papyrus, someone who we knew as a loveable, spaghetti cooking, royal guardsman seeker, who would never hurt anyone, into someone who attacks children, kills Darkners, and kidnaps the same people who he looked up to in Undertale, to be one of the most baffling decisions Toby Fox could possibly make.
You could pull any issue you want as to why it can't be any other person as the knight because you want him to be relevant and important in deltarune, which I think is a fair complaint by the way.
But in the end, should his character change like this?
Should he be the main villain despite having no connection to Kris, or any of the main cast?
I just don't see this as being good writing considering what we know about Papyrus in both Undertale and Deltarune.
I just don't think that would be satisfying, even as a Papyrus fan, and if anything would just be more upset by that as a reveal.
I think that's why I have such an issue with papyrus knight as a serious topic, because if we're going to treat it seriously as it is discussed, then we need to consider the consequences of a creative decision like that within the context of the narrative.
Whether or not you hate dess knight, or Rudy knight, or any other knight candidate that isn't Papyrus, I think any Papyrus Knight truther reading should at least consider the ramifications of that in regards to the ending of Deltarune.
That's not to say I think those people are dumb and shouldn't be talking about it anymore if they are interested in him as The Roaring Knight.
I just believe it's a bad idea, and Toby Fox should not go for it.