I often want the monster to win in the end. I am often disappointed. Universal monster movies especially adhere to this dynamic (the real ones, any Mummy movie that’s in color is shit). The “romantic lead” hero has zero personality and is only defined by his passionate and complete love for the white damsel in distress who he met less than 24 hours ago. There isn’t much “Hero” there to care about.
As an aside, the depth of stupidity displayed by the hero in the original Mummy movie is rivaled only by Mr. Talbot in the first Wolf Man. If you are given a magical talisman that will stop you from transforming into a monster or shield you from the Mummy’s death curse, for the love of all that is holy don’t give it to your girlfriend when you know damn well that it doesn’t work that way!
On to S&S stuff. Conan may be the “ultimate man” but he’s pretty predictable. He gambles, robs, attempts to rape frost giants, and hews limbs from foes until he’s king. The real interest for me is the sorcerers he battles. Thoth-Amon is my favorite character in the series. You get a powerful sense of his impotent rage at his change of fortunes. Enduring as a slave when once he ruled a kingdom with impunity. In general I find Karl Wagner and Michael Moorcock far more satisfying as they portray deeper and more complex characters with quite gray, conflicted moral standings.
The monster and the sorcerer have an insight others lack. They are connected to the unknowable mysteries of the universe (whether they want to be or not). The alien, the other, the incomprehensible reality lurking behind the mundane world, all of these are harder to portray in a point of view character. If such a character knows the secrets that the reader should only be able to wonder at, how can the author keep that knowledge away from the reader? You can play games with first and third person, but how do you retain any mystery when the main character already has the answers? This is probably why the easiest solution is to make the sorcerer a villain.
You can go the Jim Butcher route and systematize magic, but that takes a lot of the mystery out of it (I just realized that this argument presupposes that Soft Magic is the writing goal you have in mind. Doesn’t have to be, but it’s what I write, so there you go. Also, the Dresden series is excellent).
Garth Nix’s book Clariel is a very good decent into damnation story. At least the last half of it is. Unlike his other Abhorson books this one has some pacing issues, [spoilers ahead…]. He finally shows things from the point of view of a Free Magic Sorcerer (the ultimate examples of human evil in his series). It works because she is still learning the rules along with the reader and her source of information is not just unreliable but actively pursuing its own agenda at her expense. While it was a great read, I tend to only re-read the end where the main character damns herself and spirals into evil for the sake of obtaining justice and saving the lives of her loved ones. The story sidesteps the problem by not having the evil sorcerer be a master. Clariel doesn’t know the secrets that would ruin the sense of mystery about Free Magic so it isn’t something that has to be kept from the reader. She hasn’t yet turned into the monster Chlorr of the Mask that we see in the other books. We get the beginning and the end years of her life, but miss everything in between (kind of like a certain prominent biblical personage I could mention).
So here’s the question, how do you show those middle years? How do you portray a sorcerer learning their craft without glossing over all of the details you want to keep hidden on the one hand and revealing too much on the other? A Wizard of Earthsea and its spiritual grandchild Harry Potter are about this exact transition period but they tend to explain a little about the theory and leave the boring exposition about the exact nature of the world’s magical reality out. Well, that’s what Earthsea does anyway, Harry Potter is more like, “Magic works because you have inherited the proper blood, you have a wand with magic stuff shoved inside it, and you say some faux-latin.”
They err on the side of caution when it comes to exposition about how magic works (which is a good thing when you have Soft Magic to worry about). For me at least this starts to get into the territory of Metaphysics vs Storytelling because I care about the underlying metaphysics of the world in a story. It interests me (though I do try to remember that it probably doesn’t interest people who don’t read and compare religious scripture for fun). Too much exposition and too much detail gets boring fast. It moves the story away from the story and into correct but dramatically useless minutia.
I seem to have veered violently away from the original intent of this post. Which was how anti-heroes and villains are far better and more fascinating than heroes. Still, evil sorcerers are a sub-category of both, so I guess that works.
The answer I would give is to understand your cosmology and work it into every aspect of the background. Things are influenced or happen because of it, but it isn’t directly explained. Even if a novice wizard knows the theory and has the book learning, the reality is often far less precise and far more terrifying. As they said in the Constantine film, “It’s not like it is in the books.” Also consider that not everything a sorcerer is taught is correct, just like scientific theory isn’t perfect. It’s always missing huge important pieces and some of it is just plain wrong. Spirits might not always adhere to the “rules”, the rules are just the best guesses that generations of magicians have been able to come up with to explain their experiences. There is plenty of room for doubt and uncertainty and fear even for an adept to struggle with.