A tech - savvy kid who helps Spider Girl with her gadgets and technology could be an awesome supporting character. This character could also add some humor to the story. Also, a police detective who is on the verge of discovering Spider Girl's identity but also respects her work in fighting crime would make a great addition.
Her best friend from school could be a great supporting character. They could provide a normal perspective and also be someone Spider Girl can confide in. Another could be an older superhero who acts as a mentor to her, guiding her through the challenges of being a superhero.
Maybe a new superhero in training who looks up to Spider Girl. This character could follow her around, and Spider Girl would have to teach them the ropes. Additionally, an alien refugee who has unique powers and forms an unlikely friendship with Spider Girl could be a really interesting supporting character in the 'ultimate spider girl fanfic'.
One great supporting character could be Velvet. As a Faunus like Blake, she could understand Blake's experiences on a deeper level. They could bond over their shared heritage and Velvet could provide Blake with different perspectives on how to deal with Faunus - related issues. Another option is Qrow. His experience and knowledge of the world of Remnant could be invaluable to Blake. He could act as a mentor figure, guiding her through difficult situations. And finally, Penny. Her unique nature and innocent view of the world could offer a fresh take on things for Blake, and her combat abilities could also come in handy in dangerous situations.
Hermione would be a great supporting character. She could be the one who first notices Harry's interest in becoming a girl and offers her support. She might share her knowledge of magic that could help Harry in his transformation, like spells for changing appearance or potions that can affect one's gender characteristics in a more subtle way. Also, she could provide emotional support, being a good friend and listening to Harry's concerns about how others will react.
Well, first off, Captain America. His sense of honor and leadership could be a great influence on Spider - Man. Then there's Doctor Strange. He could introduce Spider - Man to the magical side of the Marvel universe. And of course, Deadpool. His wacky and unpredictable nature would add a lot of humor to the crossover. He and Spider - Man could have some hilarious banter while fighting bad guys.
One idea could be that Spider Girl has to face a new villain who has the power to manipulate time. This would put her in situations where she has to correct the changes made to the timeline. Another could be a story where she teams up with other superheroes from different dimensions to fight a common threat that endangers all of the multiverse.
Maybe a villain who can transform into different animals. He could use this power to stalk Spider - Man in the city, changing forms to blend in and then attack when least expected. This would keep Spider - Man on his toes as he tries to figure out the pattern of the villain's attacks and how to counter this shape - shifting ability.
One interesting character could be Peter Parker's aunt. She often provides a grounding force in his life and her reactions to the new girl could add depth to the story. Another might be one of Spider - Man's villains, like Green Goblin. His presence can create conflict and tension in the fanfiction, especially if he targets the new girl to get to Spider - Man.
Obviously, Spider - Girl is the main character. She's the one with the powers and the responsibility to protect the city.
How about a new villain created specifically for the fanfiction? A being made up of the combined negative energy from all the spider - verses. This entity could be called the 'Void - Spider' and it feeds on the chaos and destruction that often follows Spider - Man in his battles. It would be a very powerful and unique threat that the Spider - Men from different universes would have to face together.
Mary Jane Watson is also an important character. She has a complex relationship with Peter. Gwen Stacy is another key figure in the story. She is often involved in Peter's life and the events around Spider - Man. Harry Osborn, Peter's friend, is also a main character. His family's situation often intersects with Peter's superhero activities.
Peter Parker as Spider - Man is obviously a popular character. He's the main protagonist. Venom is often a popular character in fanfictions as well. His dark and menacing nature contrasts with Spider - Man's heroic side. Mary Jane might also be popular as she is an important part of Spider - Man's story. Another could be Harry Osborn, as his relationship with Peter is always an interesting aspect to explore in fanfictions.