Sinbad's Nemesis' Name?

Presumably your question is based on an interpretation of the name being a combination of English "sin" + "bad." But the guy's name isn't English at all, and it's proper form is actually Sindibād, which has no correlation to the semantics of sin or badness. With that in view, it doesn't sound like a very genuine lexical dilemma after all. (But that's just the way I see it.)