Two weeks from today, fellow Doctor Who nerds will be settling in to watch Amy's Choice. I bring this up for three reasons. Number one, Doctor Who is fantastic and if you're not watching it you should be. Number two, Amy's Choice sounds like it's going to be one of the best episodes this season. Number three, there are rumours afoot!
DWM takes a long time to get over here so it's not really worth subscribing unless you want to collect them, especially as people upload scans. I have yet to see scans for the latest issue, so I can't verify, but supposedly Simon Nye was interviewed in the section about Amy's Choice. In it, the villain of the piece apparently began as a virtually mute evil genius; spoke rarely, succinct, terrifying, threatening lines, and just kind of a creeper bugger. With each draft, the villain wound up having more and more to say. Still not sure he has a lot to say, as it seems like the villain won't be directly in the episode for the bulk of the narrative, but he has a lot more to say than he used to. Also the villain looks like Capote, which amuses me.
Within my own WIP, the protagonist has undergone quite a lot of changes. I haven't edited anything yet, so right now it's woefully inconsistent, but that will all be sorted in the end. Originally, Daniel was an unhappy guy with incredible acting talent which he didn't fully embrace because of his contempt for his family, but he still used it to great effect within his police life to manipulate people and events precisely as he saw it. Then Daniel was just an unhappy guy. Then Daniel was the fresh-faced new kid on the block with no idea of what he's doing. Now he's an unsure fresh-faced new kid who decides to act on impulse and backs up his decisions tooth and nail, in spite of always doubting himself while carrying out a decision, and doesn't take shit from Beckett or anyone else when they call his methods into question, and he often refuses to follow through with the methods of fellow officers blindly; seniority means nothing to him. I like current Daniel, actually. I think he's the best, most padded out, and really most realistic of all his iterations so far.
The point is, don't try to pigeonhole your characters. If you start out writing your villain or a side character in one manner, and halfway through you decide you want them to be different, don't force them to keep behaving the way they did originally. Humans grow. Me of November is radically different from me of now, and even more radically different from me of last spring. Now of course, unless your book spans a long time frame, there shouldn't be major inconsistencies of character, particularly if your character isn't a child or teenager, but during the drafting stages, who cares? If you switch halfway through the first draft, write the second to be consistent. If you change during the second, generate consistency during the third.
Yeah, during the early phases your character is probably going to look ridiculous. Wearing eighty different hats at once kind of does that. But when you find the one hat that not only fits perfectly, but looks perfect too, your character will thank you for it, and your mind will almost certainly thank you for allowing your words to flow naturally again instead of trying to force the story to carry on. And if neither of them do, you might want to look into getting a new one.