I have an idea for a character that if pulled off correctly, I think could work extremely well, but could also easily end up being terrible. She is a rather eccentric, energetic female character. She's not the main protagonist, but plays a starring roll. I want her to provide some humor, but I don't want her to simply be a comic relief character. Though she may seem like this at first, as the protagonist gets to know her (he finds her to be annoying at first) and the readers learn her backstory, she becomes much more 3-dimensional. Now, I want this character to be likable to the reader. That is the only way this character will work. The problem is, given her nature, she could just as easily be highly annoying. While the protagonist does find her to be annoying, I want the reader to like her, while understanding why the protagonist is bothered (if that makes any sense). And above all else, I DO NOT want her to become a Mary Sue. This type of character seems like she could easily go in that direction, but I know that it can be prevented. I'm trying to think of character flaws for her. Most end up being too superficial, making her too unlikable, or both. The one that seems most appealing to me is having her be somewhat of a selfish opportunist, but even that, if not done correctly, could also end up with the stated problems, and I think that flaw alone will not suffice. I really need help with this character. Do you have any suggestions?