Ace Attorney's prosecutor Miles Edgeworth became popular so quickly that creator Shu Takumi felt the need to write an entirely new prosecutor so that Edgeworth would lose less often.
When Shu Takumi created Ace Attorney, he made Miles Edgeworth out to be Phoenix Wright's rival, the prosecutor to Phoenix's defense attorney. Edgeworth has become a popular character, and that popularity has meant Takumi has had to make some changes to the series.
In an interview with Official Nintendo Magazine, Takumi explained that he largely did not make big-scale changes to the series because the scenarios for each case were completed before the characters are designed. The biggest change came in the second title, Phoenix Wright: Ace Attorney - Justice for All.
"The stories for that title as I originally wrote them all featured Edgeworth as the prosecutor," Takumi said. "However, during development of the second game, the first one was released and it became clear that Edgeworth was an extremely popular character with fans of the game."
Edgeworth is described as a brilliant prosecutor, and while he certainly is, he is determined to lose if only because he is against the player, who controls Phoenix Wright. This prompted him to create a new prosecutor, another young, genius prosecutor named Franziska von Karma.
"Of course, this meant that I had to rewrite most of the dialogue in the game completely," Takumi added.
However, Edgeworth's popularity continued - to such a degree that Takumi believes Edgeworth may be even more popular than main protagonist, Phoenix. When trying to work in Edgeworth into the games without being the antagonist, Takumi decided to include Edgeworth in the second game's final case.
"When it came to the third title it took me a while to work out how to bring Edgeworth into the story, and in the end it was with the 'turnabout' idea of having him become the player character [in Ace Attorney Investigations: Miles Edgeworth]," Takumi said. "I was already writing the story for the final case of the third game when I had this idea, but it was such a 'lightbulb' moment for me that I immediately started rewriting my draft."
The Ace Attorney trilogy will release on the 3DS as a special compilation. Capcom released a second Ace Attorney Investigations title, but it was never brought west.
Source: Official Nintendo Magazine