Perhaps the fanfiction is set in a future where Earth is no longer habitable. People live on spaceships and are constantly searching for a new planet to call home. The story could follow a family as they struggle to survive in this new reality and deal with the politics and power struggles on their ship.
Well, it could be about a world where technology has advanced to the point that humans can teleport at will. The main character, a young scientist, discovers a flaw in this system that could lead to the destruction of the universe. So, he embarks on a journey to fix it.
In such a fanfiction, one possibility is that they see a future where Naruto has finally achieved complete peace in the ninja world. He has managed to break all the chains of hatred and all the villages are united. Minato would be extremely proud to see his son's accomplishment.
In 'naruto in the future fanfiction', perhaps Naruto has passed on his ninja way to a new generation. His son or disciple could be facing a new threat that combines old and new jutsu. Maybe they have to deal with a group that has found a way to use ancient, dark jutsu in a modern, technological world.
One possible plot could be that the characters face a new, more powerful type of Grimm that has abilities they've never seen before. They have to quickly adapt and find new ways to fight. Maybe Ruby discovers a new form of her scythe's power to combat this threat.
In fanfiction, if Boruto and Sarada were married, their future could be filled with adventure. They might continue to protect the village together. Boruto, with his unique skills, and Sarada, being strong - willed, could face new threats side by side. Maybe they'd start a family and raise the next generation of shinobi with strong values.
In this fanfiction, it could be that the future has a new Dark Lord. The Marauders are brought forward in time to stop this new threat. They face challenges like understanding the new forms of magic and technology that the future Dark Lord has harnessed. They also have to deal with the fact that the future wizarding world has different social and political structures. They might start by infiltrating the Dark Lord's lair using their Marauder's Map - like skills, but find that the map doesn't work as well in the future, leading to all sorts of interesting and dangerous situations.
It could involve time travel. Maybe a character from 'the order' travels to the future and has to adapt to new magical or technological advancements there. They might encounter new forms of magic or face challenges that the future presents.
Another possibility is that it focuses on the technological future of the Arcane universe. The story could be about how new inventions in Piltover are going to change the relationship between the two cities. There could be a scientist character who watches the future of technology and tries to either encourage or prevent certain advancements based on what they see.
Well, it could be about Ladybug and Chat Noir finally revealing their identities to each other and having to deal with the consequences. Maybe they face a new, more powerful villain that is a threat to all of Paris and they have to use their combined powers in new ways.
One possible plot could be Naruto seeing a future where his friends are in danger. So, he starts training harder in the present to prevent that future from happening. He might see a powerful enemy that his friends can't defeat alone, and this knowledge gives him the motivation to gain new powers or improve his existing skills.