A more complex plot could be that there is a traitor among the Tomorrow People and Stephen and John suspect each other at first. As they investigate, they start to uncover secrets about each other and the community. In the end, they find the real traitor and strengthen their relationship through this ordeal. This would involve a lot of mystery, suspicion, and character development.
Another possibility is that it's a story of rivalry. Perhaps they both have different ideas on how to lead the Tomorrow People or deal with the outside world. This could lead to conflicts between them, but in the end, they realize they need to work together for the greater good.
One plot idea could be them going on an adventure together in an alternate universe within the Homestuck world. They could face new challenges and enemies while also developing their relationship.
One common plot idea is an alternate universe where Rose and John meet under different circumstances. For example, instead of in their usual setting, they could meet in a completely different world or time period, like a steampunk version of their story.
One idea could be that AJ and John Cena team up to face a common enemy in the wrestling world. They could train together and combine their unique wrestling styles to create an unbeatable force.
A possible plot is that a powerful enemy from the future in the Legends of Tomorrow timeline discovers the power of chakra in the Naruto universe. So, they travel back in time to try and harness it for their own evil purposes. The Naruto characters, along with the Legends of Tomorrow crew, must then join forces to stop this enemy. This would involve the Legends of Tomorrow team learning about ninjutsu and the Naruto characters learning about time - travel technology.
Perhaps there's a situation where the heroes of tomorrow are suddenly stripped of their powers. They then have to rely on their wits, training, and teamwork more than ever. They find out that an old enemy from the original Avengers' past has developed a technology that can nullify superpowers. Now they have to figure out how to get their powers back and stop this enemy before it's too late.
One idea could be a crossover where Naruto's world and the world of X - 23 from the X - Men collide. Maybe X - 23 is on a mission and accidentally ends up in the Hidden Leaf Village. She has to learn to adapt to this new place with its different culture and ninja ways. Naruto could be intrigued by her and her abilities, and they could team up to face a common enemy.
One idea could be a story where Spiderman has to team up with his greatest enemies to fight a new, more powerful threat from outer space. This would force him to put aside his differences and find common ground with the likes of Doctor Octopus and Green Goblin.
The fanfic could be set in a post - apocalyptic Asian city. A group of survivors find themselves with the anterograde ability. They have to decide how to use this power to rebuild their society. Some may want to use it for personal gain, while others strive for the greater good of the community. Along the way, they encounter various challenges, like dealing with other groups who are envious of their power.
One idea could be a crossover where the demigods from Percy Jackson meet the time - traveling heroes of Legends of Tomorrow. They could team up to stop a threat that spans across different timelines and mythologies. For example, a powerful ancient monster has been awakened in the future and is using time - travel to gain more power from the past. The demigods' powers and the time - travel abilities of the Legends would be combined to fight this foe.