One idea could be a story where Tracer accidentally travels back to the Omnic Crisis era. She could meet the younger versions of the original Overwatch founders and try to help them in ways that might change the future of Overwatch. Another could be Reinhardt going back in time to his early days as a Crusader and having to relive some of his toughest battles with the knowledge he has now.
Well, for Overwatch time travel fanfiction, you could write about Mercy traveling back in time to save a key figure who died prematurely in the Overwatch lore. This would create a whole new timeline. Or, how about a story where Winston, in his intelligent gorilla form, travels back to study the evolution of the Omnics and how they became a threat, only to find out some unexpected secrets about their origin that could change everything.
One idea could be an Overwatch crossover with the Star Wars universe. Imagine Tracer using her time - traveling abilities in the middle of a lightsaber duel. Another could be a crossover with the Harry Potter world, like Pharah flying on her rocket launcher over Hogwarts. And a crossover with the Marvel universe, where Reinhardt teams up with Thor to fight some powerful villains.
Another interesting concept could be a crossover in which the technology from TF2 is integrated into the Overwatch universe, or vice versa. For example, the Medic's healing technology being used to enhance the Overwatch medics' abilities. This could lead to some really cool character interactions and story developments as they learn to work with new equipment and each other.
A great concept could be a crossover tournament. The two teams, TF2 and Overwatch, compete in a series of challenges. These challenges could include things like a sniper - only round where Widowmaker from Overwatch and Sniper from TF2 go head - to - head. Or a melee combat round with Reinhardt and the Demoman. It would be a chance to explore the different abilities and personalities of the characters in a competitive setting.
One plot idea could be that the Overwatch heroes are transported to the Naruto universe. They have to adapt to the chakra - based powers and the different combat styles. Meanwhile, they might also introduce some of their own technology and teamwork concepts to the Naruto characters, leading to some interesting interactions and battles.
Maybe the villains from BNHA team up with some of the evil forces in the Overwatch world. Then the combined good guys, including both BNHA heroes and Overwatch agents, have to figure out how to defeat this new, dangerous alliance. It could lead to some really cool battles and character interactions, like All Might facing off against Doomfist.
One interesting idea could be Tsuna going back in time to prevent certain tragedies in his family's past. This would change the whole dynamic of the Vongola family in the present.
One interesting idea could be Itachi traveling back in time to prevent the Uchiha massacre. He could use his knowledge of future events to find a way to resolve the conflict between the Uchiha clan and the village without bloodshed. Another idea might be Itachi traveling forward in time to see the consequences of his actions and how his younger brother Sasuke has turned out. He could then try to guide Sasuke in a different direction from the future he witnessed.
One interesting idea could be the characters going back in time to prevent certain tragedies. For example, they might try to stop the deaths of some important characters. This could change the whole course of the story and create new relationships and plot twists.
One idea could be Atsushi traveling back to his own past to prevent certain tragedies from happening in his life. He might change the way he was treated in the orphanage or avoid some of the early hardships. Another idea is Atsushi traveling to a future where he has become a much more powerful and respected figure, and he has to learn from that future self to come back and save his present world. And a third idea could be Atsushi getting accidentally sent to a different time period in Yokohama's history and having to navigate through that era while also trying to find a way back to his own time.
In a Ninjago time travel fanfiction, the ninjas could be sent forward in time to a post - apocalyptic version of Ninjago. They would have to figure out what went wrong and then travel back to their own time to prevent it from happening. This could involve battles with future versions of their enemies who have evolved into even more dangerous foes.