Definitely Harry Potter and Spider - Man themselves are very popular. Harry's magical abilities and his journey of self - discovery can be paired interestingly with Spider - Man's superhero identity and his struggle to balance normal life and hero duties.
Hermione Granger is also a popular character in these crossovers. Her intelligence and knowledge of magic can be a great asset when combined with Spider - Man's street - smart nature. She could help Spider - Man understand the magical world or use magic to solve problems they face together.
Venom is quite popular in Spider - Man fanfiction. His complex relationship with Spider - Man can be explored in many ways. He can be a villain, an anti - hero, or even an ally in some really creative fanfictions. Another popular one is Gwen Stacy. Fans love to write about her and Peter's relationship, especially in alternate timelines.
Mary Jane is also very popular. Fans love to write about her relationship with Peter, whether it's the ups and downs or how she deals with Peter's double life. In some fanfictions, she might even have a more active role, like helping Spider Man in some way.
One popular theme is the crossover of powers. For example, Harry Potter getting Spider - Man's powers or vice versa. Another theme is the two characters teaming up to fight a common enemy. This enemy could be a new villain created specifically for the fanfiction or a combination of existing villains from both universes.
Obviously, Spider - Man and Iron Man themselves are extremely popular. They are the main draws as they are the two iconic heroes. But characters like Pepper Potts might also be popular as she could be involved in stories related to Iron Man's actions in the fanfiction.
Spider - Man himself, Peter Parker, is obviously one of the most popular. He is the central character, and fans love to read about his adventures, his struggles with his powers, and his attempts to balance his normal life with his superhero identity.
Eddie Brock, the human host of Venom, is also a popular character. His backstory, his struggle with the symbiote, and his interactions with Spider - Man add depth to the stories. In some fanfictions, his character arc is explored in great detail, like his journey from a bitter rival to a potential ally.
Mary Jane Watson also shows up a lot in Spider - Man and Falcon fanfiction. She can bring in the romantic aspect for Spider - Man and sometimes get involved in the adventures as well. Another character could be Bucky Barnes. Since he has a connection to Falcon, his presence can add more depth to the relationship between Falcon and the other characters in the fanfiction world.
Obviously, Spider Man himself is the most popular. He's the main character after all. But Mary Jane also often plays an important role. Her relationship with Spider Man adds a lot of emotional depth to the stories. Another popular character is Venom. His dark and menacing presence makes for some really exciting storylines when he clashes with Spider Man.
Miles Morales is quite popular. He brings a fresh perspective to the Spider - Man story with his own unique origin and powers. Peter Parker is of course always a main character as the classic Spider - Man. Gwen Stacy as Spider - Gwen also has a lot of fans in fanfiction. Her different take on the Spider - Man concept, being a female version, makes for interesting stories.
Well, obviously Spider - Man himself is one of the most popular. But in fanfiction, characters like Venom often gain a lot of popularity. In the 'Spider Man System Fanfiction', Venom can be portrayed in new and interesting ways, such as having a more complex relationship with Spider - Man. Another popular character could be Gwen Stacy. Fans might explore what could have happened if she had survived in different scenarios within the fan - made stories.