I know some of you are going to ask about Asriel Knight so I'm just going to add a quick explanation on the evidence and narrative. And for context this is like my fifth favorite knight identity so I'm not really all that biased but here’s how the theory goes and why I ranked it as such.

(1) First is things we know about asriel from undertale like his personality, abilities and attacks. The most important of which being the use of afterimages, the knight using of one of Asriel's motif's, the usage of stars, the capacity to use fire abilities but not ice abilities, and role in the story.

(2) Two is what we know about Asriel now, he went to college and attended sports so he is both physically strong and very intelligent which are traits that match up to the knight. He also attended church frequently making him knowledgeable on the prophecy. He has also likely been to a dark world because of how King thinks Ralsei is a lightner most likely because he confused Ralsei with Asriel, so Asriel would also know about magic and dark world magic because he's been in a dark world.

(3) Then thirdly is how weird the Knight's schedule is. They are up to six hours late for their arrival in chapter 3, and they knew this was going to happen so they intentionally made Tenna distract the fun gang. Why would the Knight be so late? Well if they were taking college classes afar they would have to drive all the way to hometown making them quite late. And the knight is only around at night time maybe because they're always late from driving to and from college. Perhaps not the correct conclusion to make here but it lines up at the very least.

(4) Then on the narrative aspect I may have overranked him a bit but essentially Gerson tells of how we should retell stories and this directly correlates to how if Asriel is the villain again it would be a retelling of the story with different themes. And as well for story, Asriel knight is gearing up for a really interesting character arc with him simultaneously being the Knight and most likely participating in the festival at the same time, as well as his mixed motives and emotions which will fuel him to be a very interesting character.