A great plot could be that the female super fan gets caught in the crossfire of one of Spiderman's battles with a powerful villain. Spiderman saves her, but she ends up with some sort of residual power or connection to him. This connection allows her to sometimes see through his eyes or feel his emotions. As they figure out how to deal with this new situation, they grow closer. Or perhaps she is a journalist in training, and she decides to do an in - depth piece on Spiderman. In the process of getting to know him for the story, they become friends and she uses her writing skills to help clear his name when he's wrongly accused.
One plot idea could be that the female super fan has a unique ability that she discovers while trying to help Spiderman. For example, she might be able to sense danger in a way that gives Spiderman an edge in his battles. Another could be that she wins a contest to be Spiderman's sidekick for a day, and during that time, they form a special bond that develops over time into a deeper friendship or more. A third idea is that the female super fan is actually from another dimension and her knowledge of different technologies or powers in her own world helps Spiderman in his fight against a new villain.
One plot idea could be that the female Venom has a split personality. One side is attracted to Spiderman, while the other side is a more menacing villain. This creates an internal struggle within her as she interacts with Spiderman. Another idea is that she and Spiderman have to team up against a common enemy, like a new symbiote that is causing chaos in the city. As they work together, they start to understand each other more and a romantic tension builds.
A cool plot could be that a common enemy emerges, one that is immune to Spiderman's usual web - slinging and acrobatic combat, and also resistant to the Phoenix's raw power alone. So, Spiderman and the Phoenix - influenced character (it could be Jean Grey or someone else with Phoenix powers) have to combine their skills and minds to defeat this foe. They start off not getting along well, but as they face challenges, they learn to work together.
One idea could be that Spiderman and Tigra team up to stop a new super - villain in the city who has the ability to control animals. They combine their skills, with Spiderman's web - slinging and agility and Tigra's feline strength and senses.
One idea could be that they team up to take on a new super - villain who has the ability to manipulate time. This would put their different skills to the test as they try to stop the villain from changing the timeline in a disastrous way.
One idea could be that the OC is a scientist who accidentally creates a device that can disrupt Spiderman's powers. This leads to a series of events where they have to work together to fix it while also facing off against a new villain who wants to use the device for evil. Another could be the OC is a new superhero in training and Spiderman becomes their mentor, and they develop a close bond as they fight crime together.
One plot idea could be that Spiderman gets transported into the Overwatch universe. He has to team up with the Overwatch heroes to stop a villain who has technology that can disrupt both universes. For example, Doomfist might be interested in using this technology to gain more power, and Spiderman's agility and unique powers would be useful in the fight.
One idea could be that The Vulture has a change of heart after Spiderman saves his life in a dangerous situation. He then decides to use his knowledge of technology to help Spiderman secretly against other villains. Another could be a story where they are forced to team up in an alternate dimension where they are the only ones who can stop a greater threat. A third idea is that The Vulture's daughter is in danger and Spiderman has to help him save her, which then leads to a strange alliance between them.
In a Venom x Spiderman fanfiction, a plot could involve Venom and Spiderman having to work together to stop a symbiote invasion from another dimension. The symbiotes from this other dimension are more aggressive and have different abilities. Spiderman has to use his intelligence and web - slinging skills, while Venom uses his brute strength and symbiotic powers. Along the way, they could start to understand each other better, and Venom could learn some of Spiderman's sense of responsibility. This would be a great opportunity for character development for both of them.
One idea could be that Venom and Spider - Man are forced to team up against a new symbiote villain that is far more powerful and malevolent. This new symbiote could be controlling innocent people, and Spider - Man and Venom have to find a way to stop it without harming the hosts.
One idea could be that they team up to fight a new villain who has the ability to manipulate time. This would put their different powers and personalities to the test as they try to stop the villain before he changes the timeline too much.