John DeCarli’s review published on Letterboxd:
The theme of masters and students and leadership is explored in so many satisfying ways, but Johnson adds another smaller theme to broaden Kylo's inner conflict beyond the personal: the intoxicating, self-destructive allure of burning it all down, the good and the bad. In a way, Kylo finds his own identity in the negation of everything else around him. Here, Johnson rightly furthers the motif of the silliness of Kylo's mask from The Force Awakens, casting it aside completely.
Johnson also counterbalances this theme on the complete other side of the film with the character of DJ. I've always found Finn and Rose's storyline perfunctory and awkwardly situated, but it does allow for another facet of this (a)political theme: don't choose a side between good and evil, punish the world for making you decide.