Okay, just recorded the next episode of my podcast where we finally came upon a decent theory for all of this.
I'm imagining the first hour-ish of the movie has Batman and Harvey Dent investigating the corruption, with Dent having a main role in the anti-corruption task force. The cracks start to show in Harvey's psyche during this time. At some point in the investigation, Harvey essentially uncovers that his father, AND his wife are involved in it. They are both connected to this conspiracy, which is ultimately the Court of Owls. Christopher Dent is a powerful and corrupt judge, and was incredibly abusive to Harvey growing up which caused him to develop DID. Christopher had the young Harvey temporarily institutionalized where he was further abused by Dr. Arkham, who ran experiments on his alter that caused it to become violent but it was ultimately surpressed. As Harvey got older, he wanted to pursue law like his father. It became apparent that he would not be accepting of his father's criminality and would go against the conspiracy. As a prominent member of this Court of Owls, Christopher Dent isn't going to have his son executed, but the Court needs to keep him controlled. He is set up with Gilda Gold, a member of another prominent Court family, to keep tabs on him and hopefully get him to one day accept involvement in the conspiracy. This revelation (made independently from Batman) causes his once suppressed DID alter to manifest violently, causing Harvey Dent to go AWOL. He takes on some masked persona, maybe visually similar to Hush, idk, and starts picking off the other Court members. Batman's investigation pivots to investigating Harvey, and he begins to unravel all of this, and it at a point would lead him to his family, the Arkhams/Dr. Arkham, and their history of involvement in this conspiracy. Bruce would uncover that his maternal grandmother killed her husband and then herself when she uncovered the horrors committed by her husband as a part of this creepy ritualistic cult/brotherhood that used their family institution to abuse people for centuries.
Thoughts?