3. Sophie Turner
Appeared in: X-Men film series
Fox's X-Men movie saga decided to take multiple trips into the past during its two decades of big-screen dominance, meaning that we would get to see a host of younger actors portray the titular heroes. The prequel era kicked off with X-Men: First Class but as the stories went on it began to introduce more X-Men characters.
Jean Grey didn't appear until the third offering, X-Men: Apocalypse, and Game of Thrones star Sophie Turner was cast in the role. She did a great job as the young, troubled Jean, portraying her struggles in an authentic manner. It was actually quite endearing watching Jean grow close to Scott Summers, and Turner had great chemistry with Tye Sheridan.
The character didn't possess the same emotional gravitas as Famke Janssen's portrayal, but that isn't surprising given that Turner was playing a much younger and inexperienced version of the character. And even though Dark Phoenix had a lot of problems, Turner's performance wasn't one of them, as she committed to the role in a bid to make it work.
Turner did a great job with what she was given but it would have been nice to see her introduced in some of the much stronger X-Men movies.