if she led a good life and ultimately ended up being a good person, then she would go purgatory-heaven. but it would be impossible for her to ever go straight to heaven if she was never baptised
Why can't Riddler just spend a very long time in Purgatory, then?
And you realize that Riddler had syphilis, right? He wasn't really in a proper state of mind because a disease had destroyed a large portion of his brain.
What's God's opinion on mental handicapation?
Riddler honestly believed that the extermination of the Jews would lead to the betterment of the entire world. He tried to do what was right for his people, and for the planet. Bad guys don't think they're being bad guys -- that's just stupid. Doesn't he get a little punishment curbing for his condition and the fact he was trying to improve the planet? And what about all the medical breakthroughs that the Germans discovered under Riddler's orders while doing experiments on living jew prisoners? A lot of medical science that we take for granted today is actually thanks to German doctors torturing jews. In a way, Riddler did actually improve the planet. Not to mention all the technology that came out of the arms race during the war.
So, why does he go to hell? Good intentions, broken mental state, and everyone benefits in some way from German advancements from this era. In that mindframe, you can't really blame him. Why would God punish someone like that?