One idea could be that the black suit gives Peter Parker enhanced senses that are a bit too much to handle at first. He has to learn to control them while also dealing with school and his normal Spider - Man duties.
Perhaps the black suit has a mind of its own in the fanfiction. It could try to influence Peter to be more aggressive in his crime - fighting, leading to some moral dilemmas for him. He might start to question if he's becoming too much like the bad guys he's fighting.
One plot idea could be that Black Suit Spider - Man and Black Cat team up to take on a new super - villain in the city. This villain could have a power that is linked to some dark magic, which makes the black suit of Spider - Man react in strange ways, adding an element of mystery to the story. Another idea is that Black Cat steals something valuable that she thinks is just a regular jewel, but it turns out to be an alien artifact. Black Suit Spider - Man has to convince her to return it before it attracts unwanted alien attention to Earth.
Another plot could involve the black suit affecting Peter's relationships. Maybe his friends start to notice the change in him, and he has to deal with their concerns. Mary Jane might be worried about the new, edgier Peter. Also, the suit could cause problems with his identity as Spider - Man. What if it starts to take over during his daily life and he has to struggle to keep it in check? This could lead to some really interesting internal and external conflicts.
A great plot idea could be that the symbiote actually has a mind of its own and it's trying to find a way back to its home planet. It uses Spider - Man as a host to build a device to communicate with its home. Meanwhile, Spider - Man is struggling to keep his identity and life in order while dealing with the symbiote's demands. Also, the symbiote could infect other people in the city, creating a group of symbiote - controlled minions that Spider - Man has to fight. This would add a whole new level of danger to the story.
One idea could be Spider - Man joining the Avengers on a mission to a far - off planet. He uses his agility and quick thinking to help the team out of tricky situations. Another could be a story where Spider - Man has to prove himself to the Avengers in a training exercise set up by Iron Man.
One idea could be exploring Peter Parker's struggle to balance his normal high school life with his increased responsibilities as Spider - Man. Maybe he starts to get distracted in class more often because he's up all night patrolling the city.
One idea could be an OC who is a new student at Peter's school and has a hidden power related to technology. They end up helping Spider - Man with a villain who is hacking into all the city's tech systems.
Perhaps there is a British - accented villainess in the fanfiction. She is a master of disguise and uses her accent to charm and deceive those around her. She targets Stark Industries and Spider - Man has to stop her. The contrast between her posh British accent and her devious plans would make for an interesting story. Or, Peter could be transported to an alternate dimension where everyone in New York has a British accent. He has to adapt quickly and find a way back home, all while using his Spider - Man skills in this strange new world.
One idea could be that the Agents of Shield discover Peter Parker's identity as Spider - Man early on. They could then offer him some special training or equipment. For example, they might give him a high - tech suit upgrade that has features similar to the ones in the Agents of Shield technology. This would add a new dimension to his crime - fighting in Spider - Man Homecoming.
One interesting plot idea could be Peter trying to balance his high school life with new, more dangerous threats in Queens that are not related to the big - name villains. Maybe a group of tech - savvy thieves are using stolen Stark tech in creative ways, and Peter has to outwit them without revealing his identity to his classmates. Another idea is exploring Peter's relationship with his teachers in a more in - depth way. For example, a teacher suspects that Peter is up to something unusual and starts to investigate, putting Peter in a tricky situation.
A great plot idea would be Mary Jane being kidnapped by one of Spider - Man's enemies who wants to use her as bait. Peter has to use all his skills and intelligence to rescue her without revealing his identity to the kidnapper. Also, Mary Jane could start training in self - defense secretly and ends up helping Spider - Man during a fight without him knowing it was her at first.