the great revival
It has been a year since Miles left without a trace. 
Phoenix was starting new cases again with Maya, although his newest rival is Miles' own little "sister", Franziska von Karma. Though he made no contact with his long lost friend, he kept in touch with his progress via Detective Gumshoe. Watching like a hawk, Edgeworth occasionally aided Phoenix in his case with Maximillion Galactica ("Turnabout Big Top"). Gumshoe referred to him as merely "the prosecutor", fooling Phoenix into believing he was talking about Franziska.
Franziska - obsessed with her perfection records - swears vengeance against Phoenix Wright. However, after her record was scarred not once, but twice (just like Edgeworth), finally, Edgeworth decided to emerge from the shadows. When Franziska is shot, Edgeworth resumed his role as a prosecutor. (It appears "rising from the dead" surprisingly didn't start even more rumors from the press.) Once again, Phoenix and Edgeworth meet in the courtoom.
"The Great Revival" is played as Edgeworth's new theme; the title itself signifies a change of Edgeworth's character. His original "theme" was the "Reminisce ~ DL-6": reminders of a bitter past. As the music plays out, he is no longer drowning in sorrow, but triumphant.
Though he is still a prosecutor, the truth of the matter is that Edgeworth was actually soul-searching. He went under in a self-discovering journey to understand the true meaning of being a prosecutor. It was no longer about a perfection record, nor was it to do the duty of protecting or defending a client. Pursuing the truth in the case has been Edgeworth's new goal. And in order to reach that truth, Edgeworth cannot do it alone; he needs to see both sides of the story.
Franziska Hmph, as well you should have. A prosecutor who has shamed himself with defeat should crawl into a hole and die!
Edgeworth ...But that was not what happened. After I left the Prosecutor's Office, I finally came to realize something. And it was in that moment of clarity that everything began to change.
Franziska Wh-What foolish nonsense...
Edgeworth We prosecutors use anything we can to attack the defendant. But every time we did so... No matter how desperate the situation... instead of giving up like most people, that man would hold strong with his undying faith. And then, before I knew it... I began to trust in that man as well.
Franziska Wh-What!? You trusted your enemy!?
Edgeworth It doesn't matter how many underhanded tricks a person uses... The truth will always find a way to make itself known. The only thing we can do is to fight with the knowledge we hold and everything we have. Erasing the paradoxes one by one... It's never easy... We claw and scratch for every inch. But we will always eventually reach that one single truth. This I promise you.
Pearl The "truth"...
Edgeworth Yes. That's the reason why prosecutors and defense lawyers exist.
In the Episode "Farewell, My Turnabout", Edgeworth's new character development becomes a prominent theme throughout the case. He not only aids Phoenix in words of advice, but he goes against his protocol to prolong a trial in order for the two of them to find this truth. Without his help, the real criminal would have gotten away with it... several times. Even the embittered Phoenix can't help but be awed by his turnabout.
It should be noted that his change of character didn't even started after he left - incidentally, it was his second appearance in court with Phoenix that Edgeworth slowly advanced to a brighter light. It was during the second game that he radically turned over a new leaf.