His mantra of “is there any reason this character can’t be a woman?” is so legendary that it appears at least twice WITHIN Marvel comics of the era (Strike Force Morituri 13 and Marvel Fanfare 2). As a starting point for character development, this is unique. 2/9 
C practiced what he preached, with women frequently occupying traditionally masculine roles at a level that transcended tokenism. This includes background characters (such as both pilot and co-pilot) and more featured characters (such as the genius scientist). 3/9
For the X-Men themselves, the subverted masculine roles included leaders (as recently discussed), but also muscle (such as Rogue) or the scary ninja bloodlust character (who Psylocke becomes). 4/9
Even roles that are highly stereotypical, such as Senator Kelly’s trophy wife, are portrayed with agency, compassion, and self-awareness, rare attributes for a role that normally falls into a vapid sex object portrayal. 5/9
We also see roles challenged at the narrative level, with women in traditionally male narrative roles such as martyr or sage. They are more than what author Ursula Le Guin calls “squeaking dolls …or, at best, loyal little wives or mistresses of accomplished heroes.” 6/9
As our study has established (again), Claremont’s Bechdel Test numbers are hilariously high compared to his contemporaries, indicating at least a greater prominence of women with speaking roles in his books. 7/9
Overall, Claremont portrays a cast of men and women who, to varying degrees, challenge gender roles in a wide variety of ways, effectively destabilizing (or queering) them whilst providing rare cultural examples of gender-deviant characters for young readers to identify with. 8/9
Also, we put this all together as a video essay a few months back, in case 9 tweets aren't enough and you'd prefer a more expansive treatment 😀 9/9:
