Marvel’s Dark Phoenix Saga, which the movie is based on, is dense and features a large cast of characters that Fox’s X-Men cinematic universe really couldn’t accommodate. But rather than completely passing on its chance to finally pit the X-Men against proper aliens, Dark Phoenix instead cherry-picked a notable (yet small) group of characters to highlight that have an important canonical connection to the Phoenix Force.
Early into Dark Phoenix, a number of huge, glowing objects crash to Earth near a wooded area. A human woman (played by Chastain) at a dinner party that’s particularly close to an impact site wanders off to see what’s up when her dog begins barking nonstop outside. What the woman finds is a gathering of shadowy, humanoid creatures, one of whom wastes no time in killing her, assuming her form through some very Skrull-like shapeshifting, and then returning to the party where the remaining humans are murdered as well. It isn’t until all of the aliens have adopted human guises that they begin discussing their plan with one another in their native tongue, and it becomes clear that they aren’t Shi’ar, but rather the surviving members of the D’Bari race, and Chastain’s D’Bari name is “Vuk.”