Blanche is also a favorite. Her flirty and southern belle nature gives a lot of room for interesting storylines. Fanfiction might focus on her love life, with all the ups and downs of her many relationships.
Twilight Sparkle is really popular. Since she's the main character in the original series, a lot of fanfictions revolve around her adventures and her trying to adapt to the human world in the Equestria Girls universe.
Rhyme is often a popular character in fanfiction. Her kind and positive attitude makes her a favorite. Writers like to explore her relationships within the group more deeply, like her bond with the other girls and how she helps keep the group together during tough times.
The mentors in these fanfictions can also be popular. A wise old boss, like Mr. Thompson, who guides the working girls and imparts valuable life and career lessons. His character might be well - liked as he helps the girls navigate the complex corporate world.
Sigmar is often a very popular character. He represents a powerful and heroic figure in the Warhammer lore, so many fanfiction writers like to base stories around him and his deeds.
Obviously, Blossom, Bubbles, and Buttercup are the most popular. They are the main characters after all. But villains like Mojo Jojo are also often included as they provide great conflict. Also, the Professor who created the Powerpuff Girls can be an important character in fanfiction, especially if it involves the origin story or some kind of scientific experiment gone wrong.
Galleria is often a popular character to focus on. She has such a strong personality and great leadership skills within the group. Her determination to make the Cheetah Girls successful can lead to many interesting storylines.
Professor Utonium is a popular character to include. He is the creator of the Powerpuff Girls and his relationship with them can be explored in different ways in fanfiction. Maybe he creates a new experiment that has unexpected consequences for the girls. Another popular character could be the Rowdyruff Boys as they can create interesting rivalries and storylines with the Powerpuff Girls.
Max and Caroline are the most popular. They are the main characters, and their friendship is at the heart of the show. Writers often like to explore their different personalities, with Max being the street - smart and sarcastic one, and Caroline being the more preppy but down - on - her - luck rich girl. Their dynamic provides a lot of material for fanfiction, whether it's about their daily struggles at the diner or their dreams for the future.
Blossom Z is often very popular. Her leadership skills and strong powers make her a central figure in many stories. Writers like to explore how she makes decisions in difficult situations.
The Professor is another character that often appears in fanfiction. Writers might explore his backstory more, or they could create scenarios where the Professor has to make difficult decisions regarding the girls' powers or safety. His role as the girls' creator gives a lot of room for interesting plot developments.