Maxie Zeus, I think, could qualify as having a villainous theme on par with the Joker, and the Mad Hatter.
There is so much potential with this character that hasn't been explored in Batman comics or other media. The character first appeared in Detective Comics #483 in 1979. Created by Danny O'Oneil, Maxie Zeus seems to be based on the King Tut character from the Batman television show from the '60s. He is delusional, sporting an ancient Greek theme, and believing himself to be Zeus from mythology.
Originally, he was written as an ex high school history teacher who loses his family through tragedy and builds a criminal empire (sound familiar to any Breaking Bad fans?). This in itself would be interesting enough for Gotham City, he's a delusional mob boss with a God complex fronting his criminal enterprises out of a nightclub, and leading a cult-like gang. Add an Ancient Greek theme, and you have the potential for gold. Much of the Maxie Zeus character was taken and used for other characters later on. His nightclub base of operations was borrowed and tailored to the Penguin. His cult gang was reimagined for Deacon Blackfire. Even being an eccentric mob boss, which was a fresh idea in 1979, was repurposed for older characters like Two-Face and the Penguin, and used for newer characters like the Black Mask.
However, most of his publication history shows him as an inmate in Arkham Asylum where he receives (and enjoys) electroshock treatments. Part of the Zeus theme is apparently lightning, but unlike other electric themed characters like Static Shock, Live Wire, Chain Lighnting, or Shock Treatment, he never gets actual superpowers. Sometimes he is depicted with a tazer designed to look like a lightning bolt.
Maxie Zeus's theme, like most other Batman villains, has been used for more ridiculous story lines, instead of developing a villain grounded in a realistic psychosis. The one (and really only) memorable storyline revolves around hijacking the 1984 Olympics and kidnapping an Olympic athlete. Master criminals with stupid unrealistic plots with no realistic chance of actually succeeding always make for great storylines (insert sarcastic eye-roll here, please). Unfortunately, this storyline helped relegate this character to the sidelines as a mediocre and laughable villain, along with Polkadot Man, Kite Man, and the Condiment King.
I feel like the potential for Maxie Zeus is extremely high. His original origin of a history teacher gone rogue is very much like Breaking Bad, and we all saw how good that narrative can play out. Being a charismatic cult leader brings up images of Manson, or Jim Jones. Add to that the delusion that he is a god, and there are philosophical issues like the ones Douglas Adams played with in the Long Dark Tea Time of the Soul. Why does a god need an ID to get airplane tickets? This idea of omnipotence can become scary when forces of justice meet personalities that believe themselves to be ancient, all powerful entities.
I think Maxie Zeus could be resurrected as a truly scary character. There is a combination of elements to his original premise that could equal a truly terrifying villain. The fact that so many parts have been used for other characters suggests that perhaps the time wasn't quite right in 1979.