In your opinion is there any Batman-series villains who could make a permanent switch to good? If so why?
For me a few villains come to mind:
First off I don't see Catwoman as a villain. She has been pretty firmly on the good side for a while now.
The Riddler: He had a brief run as a selfish, but mostly good detective recently. It ended up being a ruse, but I could see him someday sticking with it for the long run. The DCAU version in the comics did end up going good (but was put in a coma shortly after. We don't know if he ever recovered.)
Harley Quinn: Right now she is more good then bad. Even in her solo series, she wasn't some irredeemable monster. Yes the Joker is a terrible influence on her, but I think she is ultimately stronger than that.
Ra's Al Ghul: Why? Ra's isn't a psychopath. He is basically Bruce Wayne, Lex Luthor, and a beloved ruler of a nation all rolled into one. He has a plan to kill 99% of the human population, and can potentially achieve it, but one always gets a air of nobility and honor when it comes to him.
Poison Ivy. She was always a sympathetic villain since the post COIE reboot. Right now she is pretty much an antivillain and she did save those orphans and try her best to provide for them. She even saved some complete strangers in the GCS Christmas special. Also there was a one-shot comic called Batman/Poison Ivy: Cast Shadows where Ivy saves Batman's life out of kindness since Batman showed kindness to her previously.
Humpty Dumpty: Is he even a villain? I see him more like misguided person with a learning disability. The kind of person that an actual insane asylum is meant for. He is not full of hate or malice, but just needs help. What he did in Living Hell was bad, but he wasn't trying to cause harm.
Talia: She was good back in the 70's, 80's, and 90's. Maybe she still can be. Prior to the 00s she was basically a good person who had a really sinister father/upbringing.
Any villains you can think of that can conceivably make the change from bad to good, permanently?