Well, obviously Spider - Man and Black Widow themselves are the central characters in this type of fanfiction. But sometimes other characters from their respective universes also play important roles. For example, Iron Man might make an appearance to offer some tech support or advice to Spider - Man, or Hawkeye could show up as a friend of Black Widow's. Another popular character could be Doctor Octopus if the story involves some kind of super - villain plot. He could be a formidable foe for Spider - Man and Black Widow to 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.
A lot of times, the best writers are those who really understand the essence of the characters. They keep Spider - Man's quippy nature and Black Widow's mysterious allure intact in their fanfictions. You can often find such writers by looking at reviews and ratings of different fanfictions.
Character development is key. Maybe Spider - Man becomes more serious and strategic under Black Widow's influence, while Black Widow becomes more open and trusting. Their relationship should grow and change throughout the story. Also, the setting can add a lot. If it's set in a different country or during a major event in the Marvel universe, it can make the story more engaging.
Clint Barton, also known as Hawkeye, is very popular. Their friendship in the official stories makes it a natural pairing in fanfiction. Another one could be Bucky Barnes. The two assassins with complex pasts can create interesting storylines together.
One popular trope is the 'enemies to lovers' scenario. Since Black Cat is often portrayed as a cat burglar and Spider - Man is a superhero, they start off on opposite sides. But as they interact more, their relationship evolves into something more romantic. For example, they might constantly banter during their encounters, which gradually turns into flirting.
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.