Another possibility is that there is a villain who is stealing technology from Stark Industries (where Spiderman sometimes gets his tech) and ancient artifacts from Wonder Woman's homeland. They are both independently investigating and then cross paths and decide to work together to stop the thief.
There could be. Fanfiction writers often come up with creative crossovers. But if it's a 'lemon' fanfic, it might not be suitable for all audiences. There are other fanfics that explore the dynamic between Spiderman's quick - wittedness and Wonder Woman's strength in a more family - friendly way, like them teaming up against a common villain.
One idea could be that Spiderman gets caught in the middle of a conflict between the X - Men and one of their powerful enemies. Maybe Magneto is causing chaos in New York and Spiderman tries to stop him on his own at first, but then realizes he needs the X - Men's help. The X - Men, in turn, are initially skeptical of Spiderman but come to respect his skills.
One idea could be a crossover with Superman. Imagine Wonder Woman and Superman teaming up to fight a powerful alien threat that neither could handle alone. Their different powers and personalities would create an interesting dynamic.
The plot could involve them teaming up to stop a powerful villain who is threatening both their worlds. Spiderman's agility and scientific knowledge combined with Wonder Woman's combat skills and superhuman strength would make for an exciting story.
A cool scenario would be a battle royale - style crossover where Wonder Woman is brought into the Marvel universe to participate in a tournament. She has to fight against various Marvel heroes and villains, like Thor and Loki. As she progresses, she discovers that the real mastermind behind the tournament is trying to use the chaos to open a portal to another dimension. Along the way, she forms alliances with some of the Marvel characters and together they try to stop the evil plan.
A crossover could start with Wonder Woman being summoned to Asgard by some mysterious magic. She finds herself in a strange new world and is initially met with suspicion. Thor, being the more open - minded of the Asgardians, decides to help her figure out how she got there. Along the way, they discover that an ancient enemy from Thor's past has plans to use Wonder Woman's power to open a portal to a realm full of chaos. They then have to work together to stop this from happening, with Wonder Woman teaching Thor some new combat techniques she learned on Themyscira and Thor showing her the power of the Asgardian magic.
Maybe there's a powerful ancient artifact that has been stolen and is being used for evil purposes. This artifact has the power to disrupt the balance between different realms. Spiderman discovers some strange happenings in the city related to the artifact's power, like buildings randomly changing shape. Wonder Woman is also on the hunt for the artifact as it was stolen from a place under her protection. When they meet, Spiderman is initially in awe of Wonder Woman's strength and beauty. They team up, with Spiderman using his acrobatic skills to navigate through dangerous traps set up by the villains protecting the artifact, and Wonder Woman using her lasso of truth to find out where the artifact is hidden.
Lex Luthor could be a great villain. He could be after some technology in Spiderman's world that he wants to use to enhance his power in his own battles against Superman. At the same time, he might see Wonder Woman as a threat to his plans of world domination. He could use his intelligence to create complex traps and weapons. His corporate power would also allow him to manipulate situations in both the worlds of Spiderman and Wonder Woman.
Spiderman's agility and ability to climb walls combined with Wonder Woman's super strength could make them an unstoppable team. For example, Spiderman could use his web - slinging to quickly get Wonder Woman to high vantage points, from where she can use her strength and lasso to take on enemies. Or in a fight, Spiderman can dodge attacks and then Wonder Woman can follow up with her powerful punches.
A good crossover story idea could involve a cosmic entity that is causing chaos in both the DC and Marvel universes. Wonder Woman, with her Amazonian strength and wisdom, teams up with the Avengers, each bringing their unique skills to the table. For example, Captain America's leadership and combat skills combined with Wonder Woman's combat prowess would make for an interesting dynamic. Or perhaps a villain has found a way to merge the two universes in a dangerous way, and the only way to stop it is for the Avengers and Wonder Woman to find a way to separate them again while also dealing with the new threats that have emerged from the merge.