I assume you're talking about Joker here. What you bring up is the inherent problem with taking the tone to so dark a place that the Joker becomes such an overwhelmingly evil force that makes Batman seem utterly inept. This can be a fascinating question to explore in a Batman story, as The Dark Knight did so well, but there is a limit. When you have Joker break out every couple of issues and kill another thousand people it becomes a narrative problem because it stretches Batman as a character passed the point of credulity.
I think a good trade-off solution to this problem is to limit Joker's use. He is a chaotic entity more closely akin to a hurricane than your average hoodlum and natural disasters cease to be so shocking when they happen to your city every day. That's why I'm glad it turned out that Joker played no part in Dark Knight Rises. He was like a demon that abruptly appears and disappears in the previous movie and so it worked to keep that experience contained to allow other threats to have their place. Even though we all know he's still out there and will inevitably resurface to play the game again with Batman.
