Harvey serves to help highlight the transition of Gotham from a city of old school crime families and mob bosses to the modern age of supervillainy, creating his own criminal organization as the other mobs fall to Batman or the Bat Villains, Harvey included. I think if I was handling the DCU, I'd have Harvey start out as Bruce's friend and Batman's ally along with Gordon, and his origin happens a year or two into Batman's career.

Scenes that really explore the whole duality angle, such as the scene where Jim Gordon calls on Harvey Dent to defend him from Two-Face, are few and far between. Outside of that tragedy, Two-Face is more or less just a crime boss with a gimmick, someone who in some ways is the last of the old school mob bosses, but one who has become broken to become like the other 'freaks' of Gotham City. That most modern version have made Harvey Bruce's friend or Batman's ally from the start and who eventually gets scarred just adds to that tragedy, and creates someone you want to see saved from the horrible situation he's in. One of the most compelling things about the character is how tragic he is, how he's been so badly broken by what's happened to him that he's basically surrendered his ability to make major decisions to the flip of a coin. Freeze, Two-Face is can be difficult to work with.

Maxie zeus in casino arkham horror