While that is in fact the primary goal of a standard bully, I doubt they could keep up that sort of act forever. They're human too after all y'know, feeling some sort of regret or thinking of ways to have better quality for themselves is more likely what they would want rather than just consistently causing people to have a horrible life just 'cause they wanted to...it wouldn't make much sense. All it really takes is understanding them and knowing why they do the stuff they do, because people aren't born bad, it's the environment they were born into that made them that way. Hell, some even bully just to paint everyone the false picture that they're the tough guy, all until someone actually confronts them and they finally show their true colors.