I know it's not the fault of the creators of remixes, so I'm not blaming them, but there are companies that would claim rights to the music, however only Toby could probably do anything with YouTube doing...this! XD

Well theories can be wild haha, but yeah, so far it does look like it, plus the Knight also having niches like being left handed isn't a coincidence I would say

Oh man, the theories I had for this are too much XD

First, Dess is mutated, heavily corrupted by darkness and thus being able to kidnap Undyne who can lift cars like paper weight

Or it's a robot as when the knight is defeated, he starts glitching as to process what has been happening