His motives in choosing a career were purely 'mercenary'.
a 'mercenary' [='greedy'] businesswoman
a 'mercenary' soldier
(..) Might be time to get some fresh air. Start payin' attention to the details. Some o' those details might need your help. You check that name? Bane? He's a mercenary. No other known names. Him and his men were behind a coup in West Africa... that secured mining operations for our friend John Daggett. (..)2012 The Dark Knight Rises
(..) - Uh... You don't get to bring friends. - They are not my friends. Don't worry, no charge for them. - And why would I want them? - They were trying to grab your prize. They work for the mercenary. The masked man. - Bane? - Aye. Get 'em on board. I'll call it in. The flight plan I just filed (..)2012 The Dark Knight Rises