Funny thing is, those two have a lot in common now that you bring it up. They started as probably the most morally exemplary compared to just about everyone else in their immediate familial connections (Ben was the only "good clone" of Peter, and even Peter was headed into a downward spiral of self-destruction before Ben showed up; Obito was a pretty decent kid who believed in his friends and believed those that would abandon their friends were lower than scum), both of them seemingly died saving the life of someone they loved like a brother (Peter technically was Ben's brother on account of being Ben's genetic source material, and Kakashi might as well have been Obito's brother), both assumed the mantle of a major Big Bad after being broken down and driven insane by the machinations of the very Big Bad that originated that mantle and set about trying to "fix" the world in their own extreme ways, causing a lot of death and destruction in the process and nearly ending humanity as a whole, the revelations of their true identities broke the hearts of their spiritual brothers (Kakashi and Kaine) who tried to honor their memories . . . About the major difference between them, depending on how Spider-Geddon #5 turns out, is that Obito at least got to die with some measure of redemption (mileage may vary on whether it's too little, too late), whereas Ben ended up forced back into villainy at the end of his solo and may very well die like that.