The main character is Star Butterfly. She is a magical princess from another dimension. Marco Diaz is also a key character, who is Star's friend and often gets involved in her adventures in the fight against the forces of evil.
Well, in the Star vs the Forces of Evil graphic novels, Star Butterfly is front and center. She has these amazing magical powers that she uses to combat the various threats from the forces of evil. Marco is her sidekick of sorts. He's a normal human boy, but he's brave and always there to support Star. There are also other characters like Glossaryck, who is a very old and wise magical being that gives guidance to Star on her magical journey. And then there's Ludo, who starts out as an antagonist but his character develops more complexly as the story progresses.
Star Butterfly is the main protagonist in the Star vs the Forces of Evil graphic novels. She's a princess from Mewni with a wand that contains a lot of powerful magic. Her personality is very bubbly and she's always ready for an adventure. Marco Diaz is her best friend. He lives in the human world but gets dragged into Star's world of magic and battles against the forces of evil. Another important character is Moon Butterfly, Star's mother. She has a more serious and regal demeanor and often has to deal with the political and magical issues in Mewni. These characters together form the core of the story in the graphic novels.