Another plot could involve the return of an ancient evil that was thought to be long gone. This evil could be related to the Old Gods and start corrupting the land and the creatures in it. The heroes would then have to unite all the factions, including the Horde and the Alliance, to fight against this common threat. It could lead to some interesting character development as they put aside their differences.
A young Tauren shaman who has a unique connection to the elements. He could be born with the ability to communicate with a previously unknown elemental spirit. This shaman might lead his people in a new era of peace and harmony with nature.
A plot idea could be that a lemon tree magically appears in Azshara's territory. She believes it to be a gift from the old gods. As she tries to understand its significance, she has to face challenges from her own followers who think it's a bad omen. The lemon's power could be something that can either corrupt or purify, and Azshara has to make a choice.
One idea could be that Riley and Maya are now teachers at their old school. They have to deal with a new generation of students who are facing different but equally challenging problems. It would be interesting to see how they use their own experiences growing up to guide these kids.
One idea could be that Naruto characters are transported to the World of Warcraft universe. They could form alliances with different races like the Night Elves, with Naruto's ability to befriend others coming in handy. Another could be that the chakra system in Naruto somehow interacts with the magic in WoW, creating new and powerful spells.
A really interesting plot could be a character who is reborn with memories of a different timeline. They use this knowledge to try and prevent a great disaster that they remember happening in the previous timeline. This would involve complex relationships with other characters who may not believe their warnings at first.
Perhaps a plot where Future Gohan and Future Trunks accidentally travel to an alternate timeline. There, they have to team up with different versions of themselves to defeat a common enemy. This would involve exploring how they interact with these alternate selves and how they adapt to the new environment and challenges.
One idea could be that the Hogwarts students are transported to Azeroth. They could learn magic from the Warcraft mages while also sharing their own spells. For example, Hermione might be fascinated by the arcane magic in Warcraft and try to find similarities with her own knowledge of magic. Another plot could involve Voldemort teaming up with an evil force from Warcraft to conquer both worlds. Harry and his friends would then have to gather allies from both universes to stop them.
One idea could be a crossover with the Dragon Ball Super universe. Future Gohan could meet the present - day Goku and Vegeta. They could train together and learn new techniques from each other. Another plot could involve a crossover with the Naruto universe. Gohan might use his ki powers in the ninja world, and perhaps have to face off against powerful ninja like Naruto or Sasuke. He could also learn some ninja skills in return.
Maybe in this fanfiction, The Flash watches a future where Central City is in ruins because of a new type of meta - human threat that he has never faced before. So he starts training in the present to develop new powers or techniques to be able to combat this future threat. He could also try to find and recruit other meta - humans who might be able to help him in the future fight.
One idea could be an OC who is a time - traveler from the future. They come back to the Naruto world to prevent a great disaster that they know will occur in the future. This OC could have unique powers related to time manipulation or future - sight.