I have a planned e-book trilogy that I plan on self-publishing on Kindle. Anyways, the "archnemesis", or "Big Bad", of the trilogy is a very ruthless, wealthy billionaire who is trying to take certain artifacts away from the good guys and keep them for himself, since he believes that they belong in better hands. He allies with a very large, dangeorus organized crime group (he basically puppets this group's leader into doing what he really wants). He has a motive to destroy the good guy's secret society/organization, because he genuinely believes that it is corrupt due to once having been a part of it himself.
Added (1). I'm thinking about having had him go and witness a major humanitarian crisis (like Darfur or Bosnia), which then leads him to think that the good guys' group is incompetent/corrupt.
>>> Does this antagonist sound believable?