I have a Roaring Knight theory that makes some sense
I have been thinking and I honestly don’t like the existing theories for the Roaring Knight’s identity, first and foremost they all have plot holes, here are reasons why they don’t work: any theory for it being a Holiday doesn’t work because first of all you can’t fit the helmet on any of them (the antlers make putting on a helmet with antlers or any other shaped horn space in it impossible), and for the Dreemurrs well Asriel is at college, we see Kris and the Knight literally right next to each other, and of course Asgore would not cause an apocalyptic event because that will endanger his family, Father Alvin also cannot be the Knight because like each previously mentioned candidate his body type doesn’t work and also because he wouldn’t endanger the whole world, and even though Papyrus has a good body type to be the Knight he lacks any motivation or the evil that the Knight has, if anything Papyrus would hug a Titan. And no one benefits from the Roaring besides the Titans so that’s where my theory comes into play: What if the Knight is a being of pure darkness like a Titan that had absorbed a SOUL. After all its application that makes a Human SOUL specifically dangerous to Titans, it’s not far fetched the Knight is a Titan-like being that absorbed a Monster SOUL and gained intelligence. Also just to add insult to injury the Knight can’t be a Lightner because it can shapeshift and it’s “visor” is its mouth, in Chapter 4 it is laughing right before it makes a Titan. Anyway this theory is to explain the high power of the Knight and why it would be trying to cause something where only Titans would survive.
Summary: basically all Knight theories have massive holes in them and this one basically just says that the Knight is a Darkner with a SOUL that is not an object but it’s more similar to a Titan than a Darkner overall.
Edit: OK I realize there are major holes in my theory as well as others.