It takes a certain endurance to thrive among the X-Men, especially in the movies. Reflect for a moment on how frequently this team of misfits changes lineup: one minute a certain character is front and center, joining the ranks of Xavier’s mutants as their power comes to fruition, and then the next they are cast as a backdrop when someone more exciting (or dangerous) comes strolling through the doors, like new car models or better generations of cellphones. Only the more showy or idiosyncratic personalities ever make it past this curse of a momentary observation, and as with the source material the film adaptations have often leaned towards the same series of faces to revolve around: Wolverine (who even starred in his own trilogy of movies), Magneto (the most consistent villain), and Mystique (who has the benefit of, well, always being able to change her appearance). Now the filmmakers can add poor Jean Grey to that list of primary identities, if for no other reason than because of what her history will dictate: that she will go beyond being a normal telepath and see her mutant abilities ascend into the realms of gods and monsters. The newest chapter of this series, “Dark Phoenix,” has the distinction of casting her in that role before she is emotionally developed, which adds another challenge: how do you control yourself in a situation where everyone in the room has either lied to you or knows you must be destroyed to preserve humanity?