seconds_asunder and I know that
seconds_asunder is already writing one as we speak. I will just have to assume that when this shows up on her f-list, she reads it.
The question she posed in her journal is one I almost universally run away from and, while the advice I have to offer may sound sage and worldly to the untrained author, it could just as easily be a pile of hypothetical horseshit. I don't know, I've never needed to test it. What Tiles wanted to know (or at least, what I'm trying to offer advice about) was what to do when you're characters run away with everything you intended them to be, sell their character traits half-price at the nearest pawn shop and run naked through the streets before returning to you, dressed like a stranger and speaking in an unfamiliar accent.
The truth is, I don;t really know. Truthfully, the characters that inhabit my personal headspace are in such constant flux that all of their changes just seem par for the course. The closest I can come to personal experience is Evelyn Ross, the (now tragically replaced) protagonist of my 2009 NaNoWriMo attempt. Truthfully, the runaway character is NaNoWriMo's m.o.; they even have a forum for it. I would know. Evelyn and I spent a lot of time there. And what happened was this: everything changed. Evelyn became so different because the person I wanted so desperately for her to be just could not make my story move. She was too ordinary, too unremarkable, too realistic. The plot operated around her for all of 20,000 words...and then it stopped. I worked and worked and worked with her until she became someone else entirely. Someone just remarkable enough to maybe make the story move, but ordinary enough not to betray my initial desires.
However, in my hypothetical experience, there are a couple of hopeful answers. I say hypothetical, because Cameron, Evelyn's replacement, is doing funny things in my head, like falling in love when she's supposed to be inciting revolution among the magical population, but I haven't written it down yet. God only knows what will happen when I finally do.
Maybe we need to sit down and plan for several things to happen in the Garden, things that make Colyn the nice guy he's supposed to be, and then he can be dark in between, but the bits of planned levity will lift him out of doldrums-area gray and back into the world of what-I-intended.
I say this because character evolution is normal. It happens when you have a well-fleshed-out character that has the potential to evolve over the course of a novel. But that evolution needs to follow your plans as an author, or, at the very least, accentuate them. That evolution needs to make them more, not less than you thought they could be, or it isn't evolution and you, as the author, need to take them in hand and wrangle them back into what the plot requires.
Characters that are truly magnificent (and as someone with a front row seat to this non-sense, Colyn is indeed magnificent) can overcome this minor hurdle and walk out of their dressing room wearing some of their original clothing scraps (painstakingly rescued from the pawn show) and some new pieces (along with the new accent) and strut their stuff throughout their cannonical worlds.
Good luck Tiles!