TL;DR: The Phoenix in X-Men is about the cosmic and transcendent power of love required to heal trauma, and the films barely delve into that aspect of Jean Grey with any sort of realism or grace.
For starters, I would like to make a disclaimer that I am not talking or reviewing the comic book series. They have covered this recurring storyline often successfully, though there have been some failures along the way. But where the comics have room to elaborate and handle the core themes of what and who the Phoenix is, blockbuster films rarely do. This is not to say that it isn’t possible and I am not here to speculate on, much less reveal, the reasons the films continually fail to deliver an engaging treatment.
It is a damn shame that this story continues to fall short in cinema, however, because it is my contention that it is extremely necessary and useful to our present society.
The Phoenix Force is a cosmic entity in the X-Men/Marvel Universe that has incredible destructive powers, as well as having been credited with godlike acts of creation. It is most often associated with the character of Jean Grey, and it is through her that the most poignant and successful parts of the story get told. You see, Jean Grey possesses immense power even before she becomes the vessel of this cosmic entity, but she also possesses repressed childhood trauma. This is usually the work of Charles Xavier, who found it impossible to mentor his young charge when that trauma combined with her great powers. So, he sealed them away for her own protection and everyone else’s (in some versions of the story, he fully intends to return to these blocks/walls and help Jean heal through them, but rarely gets the chance to).
When Jean is “possessed” by the Phoenix Force, it causes damage to these mental blocks and her idyllic life begins to fall apart as the persona of the Dark Phoenix arises. The Dark Phoenix is a being of raw instincts and overwhelming desire, indulging most of all in rage. This is however, only a consequence of human incarnation and its successive identification with Jean’s fractured psyche. On its own, traveling through the galaxy, it was characterized as boundless will, power, and indifference. Cosmic forces hold no grudges–at least not for long–and this leaves the Phoenix Force as ill-equipped to deal with trauma as Jean herself is. So, paradoxically, it is an act of empathy that binds her to Jean and then subsequently twists it.
The movies are rarely able to portray this subtle work, though sometimes they come rather close. Here I am thinking of Femke’s Phoenix at the beginning of X-3 and the discovery of Jean Grey’s true past in the most recent movie, leading up to the film’s first fatal consequence. But, for the sake of thrills and CGI fight scenes, they skew the rest of the characterization required to make Jean Grey and the Phoenix Force a good character. Inevitably, her “death” is meaningless and carries none of the alchemical power the rebirth of the psyche ought to. We all know she’s coming back, even if it’s not a reboot.
These troubling modern times call for each of us mere Homo sapiens to carry a little bit of the Phoenix Force–and don’t think I miss the parallels with the flame of the Holy Ghost. Each of us has or will soon have unique traumas that come from living in the modern world, which amputates so many natural ways of being human. The climate crisis and possible collapse of civilization will engineer many more bits of trauma. To live, and to survive, we need the fiery alchemy of psyche that is only possible when we encounter the Cosmos. We cannot continue to wait for Professor X to find time to deliver us from this, no matter his good intentions.
Though there may be rage and passion, whatever breaks or dies in the firestorm will be the walls of the ego we constructed. Not because what lay beyond might harm us and others, but because we feared it. Step into those flames and be assured that, no matter what form it takes, we are reborn in the Cosmos.