By the time Phoenix bowed out of the spotlight in 2004, he had already been the player character in 12 of the series' 14 cases (over the course of three games). Frankly, his story was winding down and there was nothing more to glean from him involving his past, personality, or his relationships with the series' other main characters. Thus the only thing to do was move on to a completely new set of characters. And so the fourth game in the series came along with the new lead character Apollo Justice.
Apollo Justice: Ace Attorney was set seven years after Trials and Tribulations and featured a largely new cast. (Un)Fortunately, one of the few returning characters was Phoenix himself—and he was in no way the same as we left him. Dressing more like a hobo than
anything else, Phoenix was portrayed as a disbarred, single-father, card shark. So even though the series had a chance to explore the life and motivations of an entirely new character, the driving dilemma of the game wasn't centered around Apollo, his past, or his interactions with other characters; The dilemma was "what happened to Phoenix." So, in reality, Apollo Justice: Ace Attorney was as much a Phoenix Wright game as the previous three. And while this practically made Apollo a non-character in the whole scheme of things, it also had the effect of making Phoenix once again a character with a ton of room for development.
With the conclusion of Apollo Justice: Ace Attorney, Phoenix found his name cleared and so with his return to law, the stage is set for Ace Attorney 5. And thanks to the Apollo Justice time jump, questions abound. What happened to Maya and Pearl? Where are Miles Edgeworth, Franziska Von Karma, and the others from the prosecutor's side? How will Phoenix react being in a court after eight years on the sidelines? Will Phoenix's years as a parent have any impact on the way he handles himself as an attorney? And speaking of Trucy, what happened to Apollo and her after their tale reached its end?
Unlike back in 2004, it seems that there is much new to learn about Phoenix and he has many mysteries yet to solve. I, for one, am excited to join him in solving them.