Rodolphe is another fairly recognizable stock character – he’s a handsome, skilled Casanova, whose only goal in life is to woo women. He decides immediately upon meeting Emma that she should be his next mistress. Even at that early point, he knows that their affair will end when he’s sick of it; he contemplates how to escape from their relationship before it even begins.
We know Rodolphe is bad news, not just because he's untrustworthy, but because of how hard Emma falls for him. He’s everything she’s ever wanted – rich, handsome, smooth, and apparently sensitive (or at least, she thinks he is).
With all of these appealing traits, however, come some less savory characteristics. We are told that Rodolphe has "a brutal temperament and a shrewd intelligence" (II.7.34), a dangerous combination. He has the casual apathy of the rich classes – a downside to wealth that Emma never considers – and treats women with the same indifference as he treats his objects. Emma is no different. Sure, he cares for her and is infatuated by her beauty, but ultimately, Rodolphe is unwilling to change his life for her. He lives a profoundly selfish existence, and doesn’t care about the people he hurts along the way.