I was under the impression that she didn't want a character that people can relate to. The more people relate to a character, the more they empathize with that character, so if you want a really nasty character, you don't usually want the reader to be able to relate with them. There are, of course, exceptions, depending on what you want to do with the character. If they are going to end up doing something heroic, then you want to have some base for that. If they are supposed to be symbolic of certain human flaws, like greed, or vengefulness, then again it might be suitable to have the reader relate to the character. But if you just want a really scary villain, then for that type of character, you don't want them to be relatable (in my opinion), because their unpredictability, and their overwhelming cruelty is typically a large part of what drives the story forward. This is why I wanted to know more about the story before I commented, because it is hard to know what kind of character Nessa is going for without knowing what role they are supposed to play.
