In 2005, Rick Riordan had the brilliant idea to write about a fantastical universe where ancient Greek mythical characters are “alive and kicking.” However, the gods have adapted to the growth of civilization and developed some new characteristics: Dionysus, god of wine, is on withdrawal and drinks nothing but Diet Coke. He is unhappily in charge of a summer camp for demigods, children of gods and mortals. Mount Olympus, home of the gods, is perched atop the Empire State Building (invisible to mortal eyes), which, of course, means that the entrance to the Underworld, land of the dead, is in L.A.

Growing up as a Riordan fan, I developed a keen interest in Greek and Egyptian mythology. But, as enraptured as I was with his three series—Percy Jackson and the Olympians, The Heroes of Olympus (a spin-off of PJO) and The Kane Chronicles—I couldn’t help but notice a pattern in his character sketches that really bothered me.

No one can deny that Riordan has created some very powerful female characters. He places fierce warriors like Annabeth Chase and Clarisse La Rue on the frontline in battle scenes. His depiction of Artemis, goddess of the moon, and her immortal troupe of maiden hunters (who have swapped their tunics for camo pants and combat boots) is bordering on reverent. But he also, maybe inadvertently, puts down several female characters who are traditionally more feminine—Aphrodite, goddess of love, is portrayed as an affected diva who likes to meddle in people’s love lives. Most of her demigod children are vain and have skills that are of little use to Camp Half-Blood, and their cabin is described as “decorated like a Barbie house” where “supermodels go to die.” The final insult comes in the form of her daughter, Piper McLean, who is revolted to find out her godly parentage.

This demonization of femininity is not unique to Riordan. Many male authors find the need to create heroines who are unmistakably “tomboyish,” and who despise all things pale pink or frilly. Although the intent behind this is to empower these characters and, consecutively, the preadolescent girls who idolize them, it is inherently sexist because it assumes that femininity is weak. I can’t stress enough how damaging a message like this is to a young girl’s psyche—finding your identity as a teenager is confusing enough as it is. Adding to it, characters like Piper McLean, who has a huge “not-like-other-girls” complex, shame young girls with naturally feminine tastes. It also suggests to young boys that women who don’t show outward toughness somehow deserve less respect and are, therefore, at the mercy of the men in their world.

To Riordan’s credit, however, the vilification seems to reach its peak with Piper. Sadie Kane, who first appeared in 2010 in The Red Pyramid, the first book in The Kane Chronicles series, is more realistic. At twelve, she is moody, chews a lot of gum and wears combat boots. But she also wears a chic dress and light makeup to her school dance. She is much closer to the idea of a real adolescent girl than most of the heroines in the other two series because her personality grows and changes substantially through the series. More importantly, she’s respectful of other people’s tastes, even when they don’t match her own.

Despite giving the impression that they were all initially built from the same mold, Riordan’s heroines are inspirational to say the least. In the world of Greek mythology, which is the definition of a patriarchy, the idea of female heroes who go on quests with their male peers as equals is a novelty that the heroes take in their stride. The three series also address issues like racism and homophobia, which is rare for young adult fiction published around the same time. As a loyal reader who stuck with Annabeth and Sadie and their respective gangs till the very end, I hope to see more strong women with diverse personalities on the pages of Riordan’s future books.