The war campaign that my friend is going to run revolves around an evil prince/princess who hopes to become a god. Ultimately though she is understandable because the whole world (or at least this one material plane) is in an endless free for all. Sure she might kill thousands while uniting the plane, but it will end the war and save thousands more in the end. The whole "becoming a god via the people's worship" is just her reward at the end of the day.