I think he's just. A guy.
A guy who didn't want to be forgotten, and out of desperation and selfishness, did some bad stuff. Sure, he wanted to plunge the entire world into sorrow, but I like to think that by that point he was so strung-out after lamenting and trying for years, that he just couldn't take it anymore. Come on, there's been a time where you were so fed up you wanted to forsake the world. Does that make you evil?
Good guys do bad things. Bad guys do good things. It doesn't have to be black and white.