2. Lock-Up
Who Is He? Lyle Boltonbetter known as Lock-Up, because comic books are never short on puns is unlike any other member of Batman's rogues gallery, because he seems to be the only one that isn't trying to break OUT of custody on the reg. First appearing in "Batman: The Animated Series" as a troubled Arkham Asylum security guard who got tired of the system's revolving door policy, he was quickly adapted into the comic canon proper and added to Batman's list of troubled foes. Lock-Up's entire motivation is to punish those who he feels broke social crimes (like the media for glorifying criminals), and goes to great lengths to ensure that they are imprisoned without all that due process nonsense. Because he never really got the gist of how to keep his inmates under his thumb in a legal sense, Lock-Up has become one of Batman's perennial losers that has never really made much of an impact.
How Should He Return? Lock-Up is a ridiculous character with a pretty cool premise. He could be brought back as a master strategist with a knack for creating complex maximum prisons for his inmates, full mayhem creating nonsense like trap doors and sharks with lasers attached to their heads. Lock-Up doesn't need to be an imposing Bane-ripoff to be effective. Let his mind do the flexing, and put it to work on trapping Batman in a prison he'll actually have trouble escaping from.