Some fanfic could be about the alternate realities that could have occurred if certain factors were different on the plane. For example, if the terrorists had been detected earlier or if there had been more communication between the cockpit and the passengers. It could also be a story about the investigation that might have taken place on the plane had there been a chance. And perhaps a fanfic about the hope that still lingered among the passengers even in the darkest of moments.
One interesting concept could be alternative timelines. For example, what if Harry had been sorted into Slytherin instead of Gryffindor? It would completely change his relationships and the way he approaches magic. Another concept might be a different family background for Harry, like if he was raised by different relatives. This could lead to a different personality and set of skills.
One possible scenario could be that the magical characters find themselves on a Muggle plane due to some strange magical accident. Maybe they were trying to apparate but got misdirected into the plane. Then, when the plane starts to crash, they use their magic to try and save the day, like Harry using a spell to slow down the fall or Hermione creating some sort of magical shield to protect the passengers.
Some popular non - sex - related marichat fanfic concepts could be adventures they go on together in Paris. For example, they might team up to solve a mystery involving a new akuma that has unique powers. Another concept could be them sharing their artistic sides, like Marinette showing Chat Noir her latest fashion designs and Chat Noir sharing his thoughts on poetry or music. Also, stories about them just having friendly conversations on rooftops under the moonlight, getting to know each other better as friends without any romantic or sexual undertones.
Another concept could be a fanfic that centers around a time - travel plot. Maybe a character goes back in time and tries to change certain events, but not in a way that involves inflation. It could be about preventing a small tragedy that had a big impact on a character's life, and how that changes the course of the 'Naruto' story.
One concept could be a crossover where Naruto and Kim Possible team up to take on a common enemy that threatens both their worlds. For example, a powerful ninja from Naruto's world who has found a way to access Kim's world and is causing chaos. Another idea is a story where Kim and Naruto accidentally swap places due to some magical or scientific mishap. They then have to adapt to each other's lives and use their unique skills to keep things running smoothly.
Another possible character could be a scientist or an engineer on the plane. This person could use their knowledge to try to repair some sort of communication device or build a more effective shelter. Their skills would be very useful in the situation, and they could form a sort of team with Beckett to increase the chances of survival for everyone.
A fanfic concept could also be Ruby exploring other kingdoms in the RWBY world. She could go on a diplomatic mission or just be on a journey of discovery. Along the way, she would meet new characters, learn about different cultures, and of course, face some Grimm and other challenges. This would expand the RWBY universe from her perspective and create some really engaging stories.
In some fanfics, Naruto may be sad because of unrequited love. He has strong feelings for someone, but that person doesn't return his feelings. Naruto is a very emotional character, and love is an area where he can be easily hurt. So this could be a source of his sadness in the fanfic.
Perhaps they start off as enemies, not knowing their relation. But as the story unfolds, through various battles and interactions, they begin to suspect that there is more to their connection. It could be that they both have a strange mark on their body that is only found in their family, which leads them to uncover their relation. And then they have to decide whether to continue as enemies or join forces.
In a 'human's breed by pokemon fanfic', one possible concept could be the idea of humans having some sort of genetic or magical connection to Pokemon that affects their breeding. Maybe it involves a special power that Pokemon transfer to humans which then alters the way humans reproduce. For example, it could be that certain Pokemon traits are passed on to human offspring in this fictional world.