To avoid prejudices and double standards, it´s never bad to switch between the protagonists´ and antagonists´ perspectives and, why not, write whole parts of a series from different viewpoints.
I´ve seen close to not other fantasy and dark fantasy author doing this, thereby giving it an extra, deep, substantial layer of philosophical undertone and completely understandable explanations for the mentalities implemented in the melancholic, depressing, and hopeless dark fantasy wasteland.
One of the most important insights is that evil, duh, doesn´t see itself as that bad. It´s just as if a lion, bear, or any flesh eating animal would be seen as evil murderer, because it needs the death, or in the case of black magicians and witches, at least suffering and weakening by parasitizing, of others to survive. Of course, we are no animals and this would thereby be a very cheap excuse, but if there would really be magic powers and one could just get big on the dark side, it´s at least understandable. Or if her/his talents are just onesided, what should the person do, not use them and unleash the full potential because of unrealistic, altruistic, moral, and ethical questions?
Lukianenko implies that the destructive and bad, easy way is far more lucrative and seductive, all thanks to human nature, because the having lesser power, being friendly and helpful, rainbow unicorn way just isn´t realistic for predatory, carnivorous apes, just as vegetables are hardly ever beaten by a bloody, medium filet steak. Must suppress the evil voices in my mind,… drooling.
One can see it in real life, being a friendly, motivated, sober, recycling, vegetarian, eco friendly, open minded, etc. person isn´t as sexy and fun as being a drunk, egoistic, hateful, etc., well, much more realistic person. And so, in Lukianenkos´ world, we are the livestock, cattle, and brain food, and the inner struggles and subjective paths of the higher evolved magic fractions decide whether we are slaughtered or cared for with interspecies love. Because, of course, to a certain extent, evil can do good and good evil, which complicates the dynamics between not so good, closer to evil and not evil enough.
But, not as in a real life where evil rules everything, a balance, rules, even courts, a bonus malus rating system are implemented to make sure that the power balance stays intact, no war breaks out, and each side has it´s primal goals and cozy or bloody scopes. At least as long as nobody beyond all categories comes witching around.
Heck, in real world, this would be like everything evil in one half of the population and an angel fairy government on the other side, each one with its own secret services, specials forces, investigators, etc. It´s no wonder that this genre, like Butchers´ Dresden files, is exploding, because putting the stereotypical dark fantasy, mythology, and fairytale inspired tropes into new, funny, disturbing, mind penetrating, subtle criticizing contexts is a great recipe for grey reading pleasure between boring, stereotypical white and black fractions.