One idea could be a crossover with the X - Men. Spider - Man could find himself in a situation where he has to team up with the mutants to fight a common enemy that is using the symbiote technology from 'Web of Shadows' against both groups. Another plot could involve a crossover with the Fantastic Four. Maybe the symbiote invasion in Spider - Man's world starts affecting the Negative Zone, and they have to work together to stop it from spreading further.
Well, a plot could be a crossover with the Hulk. The symbiotes start infecting people in a small town near where the Hulk is hiding. The Hulk initially thinks they are just normal threats but soon realizes they are something different. Spider - Man arrives to deal with the symbiote situation and has to convince the Hulk to not just smash everything but work together. They could form an unlikely duo to take on the symbiote - controlled enemies. And perhaps there could be a sub - plot where Spider - Man tries to keep the Hulk from getting infected by the symbiotes, which would be a huge disaster if it happened.
One idea could be exploring what would happen if Spider - Man had to team up with his villains to fight a greater threat from another dimension. For example, Venom and Green Goblin might be forced to work with him.
A plot could be that Black Cat gets infected by a different kind of symbiote that gives her new powers. She has to learn to control these powers while also dealing with the fact that Spider - Man is a bit suspicious of her new abilities.
One idea could be that Spider - Man discovers a new shadow - based villain who can manipulate the darkness in ways he's never seen before. The villain could be creating shadow creatures to terrorize the city at night.
One idea could be that Spider Man gets transported to an alternate dimension where he meets different versions of his female friends and allies, and they all have feelings for him. For example, Mary Jane from a noir - styled universe, Gwen Stacy from a steampunk world, and Felicia Hardy from a magical realm. They all team up with him to fight a common enemy while dealing with their romantic feelings for him.
One idea could be that Naruto is somehow transported to New York City and meets Spider - Man. They team up to fight a common enemy like a group of ninjas who have also been brought to the city by some sort of magic or science experiment gone wrong. Another plot could be that Spider - Man gets some of Naruto's powers and has to learn how to control them while still dealing with his normal life in the city. Maybe the symbiote from Spider - Man's story could combine with some of Naruto's chakra and create a whole new kind of threat that they have to face together.
One idea could be that Deadpool and Spider - Man team up to take on a new supervillain who has the ability to manipulate time. Spider - Man uses his quick thinking and acrobatic skills, while Deadpool's unorthodox fighting style and regeneration ability keep them in the fight.
One idea could be a crossover with the X - Men. Spider - Man could find himself in the middle of a conflict between mutants and anti - mutant forces. He'd have to use his quick thinking and agility to help the X - Men protect the young mutants. Another could be a crossover with the Fantastic Four. Maybe Spider - Man gets caught in one of Reed Richards' experiments gone wrong and they all have to work together to fix it while also dealing with a new super - villain that emerges from the chaos.
Definitely Wolverine. His healing factor and berserker rage would make for an interesting dynamic against the symbiotes in 'Web of Shadows'. Another great character is Captain America. His leadership and moral compass could guide Spider - Man in a situation where the symbiote - influenced chaos is causing moral dilemmas. And Daredevil could also be a good addition. His enhanced senses could help detect the symbiotes in ways Spider - Man might not be able to.
A fanfiction could focus on Black Cat's backstory within the Web of Shadows context. Maybe she has a secret past connection to the symbiotes that is slowly revealed as she battles against them. This would add depth to her character and her role in the story.
In the context of Spider - Man: Web of Shadows' evil ending fanfiction, one interesting aspect could be the character development. If Spider - Man goes down the evil path, how do the other characters react? For example, Mary Jane might be horrified and try to bring him back to the good side. Also, villains might either team up with this new, evil Spider - Man or see him as a threat to their own plans.