Here's my prediction for Riddler's story.
Edward was a poor kid. They said if you work hard, get good grades, you can make something of yourself (smart = successful. Only the intelligent survive), and so Ed makes that his goal. But turns out darwinistic capitalism is a little trickier than that, especially if you have mental health issues as Ed does, and if your family can't support you, whereas someone like Bruce just walks into whatever college he pleases because of his family name. So, Ed goes nowhere in life, and like Bruce, he becomes a bitter recluse.
Edward uncovers that a group of powerful wealthy Gothamites (Waynes included) halted the construction of a very expensive, but very necessary seawall to account for rising tides in the decades to come, which if left unaddressed, would start flooding the poorer neighbourhoods of the city.
Ed lives a lonely life, so in his last ditch effort to make something of himself, he turns to "true Justice", like Batman, to be a "hero" for Gotham's poor, donning a mask, a name, all that. First, he goes after the politicians who aren't really going to change anything, especially since they're all in bed with the city's criminal underworld anyways, and then attempts to drown the "cesspool of a city" (ala Zero Year), expediting the process, showing the rich how much they were screwing the poor, and making them all pay for lying, for ignoring the plight of the less fortunate and the mentally unstable.
This is how he's going to make people take notice, by levelling the economic playing field, only allowing the intelligent to survive, as that was what he was told that life was all about. And though he says he's doing it for justice, really it's vengeance. He wants to dig the knife into those more fortunate than him, and those who had been turning a blind eye, like Bruce.