One interesting storyline could be Peter Parker trying to balance his superhero duties with his relationships in the harem. For example, he has to keep his identity a secret from some of the girls while still being there for them. Another could be the different dynamics between the characters in the harem, like a love - hate relationship with one of them.
In some Peter Parker MCU harem fanfictions, a great storyline is when the harem members start to discover each other's powers or abilities. This can lead to both cooperation and competition among them. Also, there could be a storyline where Peter has to choose between his loyalty to the Avengers and his new - found relationships in the harem, creating a lot of internal conflict for him.
MJ is an obvious choice. She has a connection with Peter in the MCU already. Then there could be Gwen Stacy, who is a classic love interest in the Spider - Man lore. Another potential character could be Black Cat. Her flirtatious nature would add an interesting dynamic to the harem.
Perhaps a fanfiction could be centered around Peter being accidentally transported to Carol's part of the universe. He has to rely on her to get back home. During this time, they encounter different alien species and face various challenges. Carol helps Peter understand the vastness of the cosmos while Peter shows Carol the importance of small - scale heroics. Their relationship could evolve from just teammates to close friends, and maybe even something more, as they overcome these obstacles together.
One interesting storyline could be Peter using his spider - abilities in a ballet - related way. For example, his enhanced balance and agility from being Spider - Man could make him an exceptional ballet dancer. He might incorporate his acrobatic moves into a unique ballet performance that wows the audience.
Well, in some fanfictions, Hydra could create clones of Peter Parker. These clones might initially follow Hydra's orders but then develop their own sense of self and rebel against Hydra. It could also be that Hydra tries to brainwash Peter, but his strong moral compass helps him resist and turn the tables on them.
One interesting storyline could be Peter Parker using his scientific knowledge to upgrade the Avengers' technology. For example, he might create new web - based gadgets for himself that also have applications for the team. Another could be Peter's struggle to fit in with the more experienced Avengers, like trying to prove himself during a tough mission. And there could be a storyline where Peter discovers a new power and the Avengers help him master it.
One interesting storyline could be Peter using his wealth to upgrade his Spider - Man gear on a whole new level. He could create high - tech suits with advanced features like self - healing capabilities or enhanced camouflage. Another could be him funding scientific research to find a cure for the villains he faces, instead of just fighting them physically.
One interesting storyline could be them teaming up to solve a mystery in their neighborhood that the Avengers overlooked. Maybe it's a small - scale tech - related mystery that Harley's engineering skills and Peter's spider - sense can combine to crack.
One interesting storyline could be Peter Parker gaining the ability to control thunder and lightning in addition to his spider - powers. Maybe he has to face a new villain who can also manipulate electricity, and he has to figure out how to use his new powers to defeat this foe.
A really cool storyline could be that the Web of Life starts to malfunction and Peter Parker is the only one who can feel it. As he delves deeper into the problem, he finds out that it was caused by an experiment gone wrong in another universe. He then embarks on a journey through the Web of Life to find the source of the problem and fix it, all while facing various challenges and making new friends along the way.
A possible storyline is Kaine Parker getting accidentally transported to the Guardians' territory where Peter Quill is. Their clash of personalities, Kaine's more brooding nature against Peter's carefree space - faring attitude, could lead to some really engaging character - driven plots. They might start off as distrusting each other but then gradually form an alliance.