A Joan-of-Arc feMRA refers to a woman who claims to want to advocate for men and boys, but will only do so on the basis that she leads the charge and acts as men's official mouthpiece. Such women expect men to act as a ready army of gophers who will do research, web design, phone calls and a myriad of other tasks that she delegates them, and generally expects men to treat her with deference and big lashings of chivalry. She does not tolerate men speaking in their own voice (not through her) and insists on controlling all matters related to policy and activism. Paradoxically, the Joan-of-Arc feMRA represents a mixture of gynocentrism, narcissism, and men's rights advocacy.
Joan-of-Arc feMRAs love the limelight and will take every opportunity to put a photo of themselves on prominent media pages, while declaring her self-importance in the role of 'Liberator Of Men'. Most Joan-of-Arc feMRAs will eventually fall out with the men they claim to represent when said men eventually call her out about her control issues, and she responds to the criticism like a raving termagant who spits the dummy and refuses to support men any more.
Fortunately, and mercifully, not all feMRAs are like that.