I think that when it comes to interest, it's always down to you. If you like your characters and treat them like they are interesting with unique life stories, someone else will be interested, too. You can't play your character or create them just to make them interesting for others, but if you go into it considering them interesting and wanting to share them with others, I think people will respond favorably.

One big thing I've learn is that you shouldn't...treat them like "original characters"? If you treat your character the way you would any other character from a fandom canon, people aren't as wary about playing with them.