In the original Star Wars trilogy, generals like Hux had the tendency to die at an alarming rate – sometimes by getting Force-choked by Darth Vader – but The Last Jedi subverted expectations by allowing Hux to avoid such a fate.
At the end of Star Wars: The Last Jedi, it certainly seemed that Ren was ready to take up Snoke’s role as Supreme Leader.
Domhnall Gleeson says he was surprised General Hux survived Star Wars: The Last Jedi.
But that allowed Hux to return for The Last Jedi, still locked in a power struggle with Supreme Leader Snoke’s apprentice Kylo Ren.