The film includes Porthos as a bisexual character, integrating this aspect subtly into his identity for diversity. However, LGBTQ+ themes are not central to the narrative, which focuses on historical adventure and political intrigue. The portrayal is incidental, neither uplifting nor denigrating, as it avoids detailed exploration of LGBTQ+ experiences.

The film features Milady de Winter, a highly skilled operative, who repeatedly engages in and wins close-quarters physical fights against multiple male guards and adversaries using knives and hand-to-hand combat.

Constance Bonacieux, traditionally depicted as white in the source material and previous adaptations, is portrayed by Lyna Khoudri, an actress of French-Algerian (North African) heritage. This casting introduces a visible ethnic diversity not present in the novel's traditional depictions, constituting a race swap for this character.

The film portrays religious divisions between Catholics and Protestants as a significant source of societal ills, violence, and political intrigue in 17th-century France. The narrative uses these conflicts as a backdrop to highlight the destructive consequences of religious factionalism rather than affirming the faith itself.