Taken from another thread to be moved here:
Good and evil are subjective terms. From his point of view, heroes are very evil
I'm not going to boil this down to philosophical subjective terms. In the Elder Scrolls setting, he is evil, heroes are good. In addition, what's to say he doesn't consider and know himself to be evil but revel in the fact that he is, and as such, still see heroes as good?
In Elder Scrolls terms, there is no good or evil. It's all relative. There are creators and destroyers, but neither are good or evil. TES is never that black and white.
That being said ZOS seem to be presenting it in a more good vs evil sense which I'm not really happy about.