For my main, I have a rather cool method of thinking as to why she kills so much when her intentions are initially altruistic. The way I look at it, the Dovahkiin is a dragon's soul incarnated into the body of a mortal. Such a thing would present inner conflict I think, a clash between mortal morals and ideals vs. Draconic instinct and hunger for power. In the heat of the moment, when facing down enemies, a raw instinctual drive to dominate takes hold of my character's mind, especially when facing an especially dire opponent. When all is said and done, and her bloodrage subsides, and she sees the carnage she's wrought, she hardly feels she's better than the dragons she's fighting, as all she brings with her is destruction. It leaves her feeling dehumanized and disgusted with herself. But she can't stop, as she has a duty towards destiny to defeat the great evils that would threaten Skyrim and the world. She takes up arms against threats like Alduin, Harkon, and the first Dragonborn because she feels she must protect humanity. But her dragon soul relishes the moment she is able to topple another powerful being and assert her own power, something she will not admit. She has to fight against her congenial nature, much like Parthunaax, and unlike Parth, she has to question whether or not she is really human. (She also spared Parth, because at that point, she began to feel and odd and inexplicable kinship with dragons, and began to feel bad for even killing them in the bucket loads) Overall, my character is not a happy camper. She's more like my Nerevarine, who also had to constantly question his actions, and what the consequences of them were, and with the vanishing of Vivec and the eruption of Red Mountain, followed by the fall of Morrowind, his immortal ass felt far from being a paragon of his people. I'm pretty sure he's living in isolation somewhere in Akavir now (If not canonically, than in my mind, my specific character is) I like characters with flaws, who realize that their hands are stained with the blood of hundreds upon hundreds of people.