A lot happened in "X-2: X-Men United," including the alleged death of Jean Grey. It had set up the storyline for a possible story about the dark phoenix, but Brett Ratner had other ideas ... which failed miserably for fans of the comics.
A myriad of fans felt that Ratner had no business even being involved with the franchise since his previously biggest success was the almost racially offensive "Rush Hour." He'd managed to almost bring the franchise to its end, with the help of Gavin Hood, the man who tried to give Wolverine an origin and instead gave Gambit a 5-minute walk-on role and turned the merc with a mouth into a mute his fans barely recognized.
Thankfully, both the franchise and Ryan Reynolds came back from this and have proven to be worth another chance.
The problem with introducing Phoenix now
We've barely had a chance to even get to know Jean Grey since she had her re-cast debut in "Apocalypse," and already they're giving her a story about how she unlocked her mind and learned to channel her uncontrollable full potential. She was barely a student the last time we'd seen her, and now she's on the verge of becoming a major villain.
Even the "death" of Professor Xavier could have opened up the story to the story of Onslaught, a villain created when Xavier and Magneto meshed their minds together in the latter's body and became insane in the end.
They still haven't rebooted Juggernaut, and he's the brother of Charles Xavier, who we've seen a lot more of since James McAvoy took over.
It almost looks like 20th Century Fox is trying to follow the example of Warner Bros. Pictures with their DC expanded universe. It appears they're speeding things along and rushing out major stories before they're ready.
Rushing in this way may end up "cheapening" the story and losing much of the fan base.
Sophie Turner might surprise us as a villain
Admittedly, Turner didn't get a lot of screen time in "Apocalypse," other than to predict the end of the world, basically turning her character into little more than a plot device. Quicksilver actually received more of a focus and ended up being many fans' favorite part of the movie.
Other than her short career including the role of Sansa Stark on "Game of Thrones," we don't have much to judge her by.
Many actors often don't get much attention until they portray a villain. Of course, the Dark Phoenix is almost a villain in spite of herself, as the essence of the Phoenix is actually a kind of force which takes over her mind.
"Dark Phoenix" could go either way, but hopefully 20th Century Fox will get it right.