One question that has long plagued the minds of Buffy the Vampire Slayer fans is why has there never been a male Slayer. The Slayer line has always been comprised of women. It's clear that the creative choice is a deliberate feminist one made to subvert audience expectations, with Buffy taking the deceptive appearance of the average horror movie victim (blonde, sassy, always falling down, etc.) Most audiences recognize the metaphor, but it's never been symbolized in canon during the TV show as to why the Slayer line is always women and never men—but now fans have an answer!
It isn't until the 12th season of Buffy (outlined in a comic continuation) that audiences finally receive clarity on the issue, thanks to Harth, who is a vampire master and the season's Big Bad. To combat him, Buffy has Willow conduct a spell that would give her the powers of all active Slayers. However, moments before she could consume that power, Harth jumps into the way, taking the power for himself.
In Buffy the Vampire Slayer Season Twelve (by Christos Gage, Joss Whedon, and Georges Jeanty), Harth can only hold the power for so long before succumbing to it, unable to cope with the psychological toll that a Slayer's power holds. As Giles explains, men can take the power of a Slayer, but they cannot endure it. Men simply are not capable of bearing the powers and memories of a Slayer without going mad. Harth, because he is a soulless vampire and the twin brother of a Slayer named Fray, lasts longer than most men would, but even he can't do it because of his gender.
Men Aren't Slayers Because Women Are More Resilient
A similar sentiment would be echoed years later in Buffy, the Last Slayer, where Anya explains to a much older Buffy why Slayers are always teenagers. She suggests that only children are brave enough to challenge evil, whereas adults don't have the same mental fortitude or willingness to fight after spending most of their lives being complacent. Both of these explanations combined give a full overview that essentially summarizes that young women have to endure much more weight on their shoulders than the average men.
In that regard, when life already gives women a heavier load of responsibility, women are best equipped to be Slayers. Men, on the other hand, when they are not used to having to carry so much weight on their shoulders in their life, carrying on such weight as a Slayer would be too emotionally, physically, and mentally taxing for a man. This is the best way to understand why men can never be Slayers in the lore of Buffy the Vampire Slayer.
