One idea could be Link from Ocarina of Time getting transported into the World of Light and having to learn new combat styles to fight the enemies there. He might meet characters from different Nintendo universes and form unexpected alliances.
Perhaps in this fanfiction, the villains from Ocarina of Time also find their way into the World of Light. Ganondorf could team up with some of the World of Light's native villains. Link would need to gather all the sages again, but this time in the unfamiliar World of Light setting to stop this new, more powerful evil alliance.
A great plot for 'ocarina of time crossover fanfiction' could be a crossover with the Final Fantasy series. Link could meet characters like Cloud or Squall. They could exchange combat techniques and magical abilities. For example, Link could learn some of the complex spellcasting from the Final Fantasy mages, while the Final Fantasy characters could be intrigued by Link's use of the Ocarina. Or perhaps a crossover with the Pokémon world. Link could befriend Pokémon and use them in his quests, while also teaching the Pokémon trainers about the ways of Hyrule.
A great idea for zelda ocarina of time fanfiction is to imagine an alternate ending. What if Link failed to defeat Ganon? How would the world be different? You could also write about Link training with the different sages before facing Ganon, showing his growth in power and knowledge. Additionally, a story about the origin of the Master Sword and its connection to the Ocarina could be very interesting.
One idea could be exploring Link's time in Kokiri Forest before he sets out on his adventure. Maybe show his relationships with the other Kokiri in more detail. Another could be a story where Zelda has to take on a more active combat role instead of just being the damsel in distress. And a third idea might be a fanfiction that delves into the backstory of the Ocarina itself, like who made it and what secrets it holds beyond what we see in the game.
One unique idea is exploring the dark side of the Triforce. In some fanfictions, after Ocarina of Time, the power of the Triforce is misused or has unforeseen consequences. Also, there are fanfictions that focus on the Sheikah tribe's role in the post - Ocarina of Time world. They were important in the game, and these fanfictions expand on their influence, like how they might be involved in protecting ancient secrets that could change the future of Hyrule.
One interesting concept is alternative timelines. Fanfiction might explore what would happen if Link made different choices during his adventures. For example, if he didn't pull the Master Sword at a certain time. Another concept could be character backstories. Writers often expand on the pasts of characters like Zelda or Ganondorf, adding more depth to their motives. There are also fanfictions that focus on different relationships, like a deeper friendship between Link and Saria that wasn't fully explored in the game.
One idea could be to have Naruto find the Ocarina of Time in the Hidden Leaf Village. Maybe it was left there by a wandering traveler from the 'Ocarina of Time' world. Naruto, being curious, starts to play it and unknowingly opens a portal to the world of 'Ocarina of Time'. He then has to navigate this new world, using his ninja skills and making new friends and allies there.
Ganondorf would be an obvious choice. Since he is the main villain in Ocarina of Time, he could continue his reign of terror in the World of Light. He might even gain new powers or form alliances with other dark forces in this new world.
In some fanfictions of this type, the reincarnated Link might have to deal with the differences in time perception. Since they come from a different world, time might work differently for them. This could lead to some interesting situations like they age at a different rate or they can predict events based on their strange sense of time. They could also have an internal struggle as they try to balance their modern - day morals with the more archaic ones of the Hyrule world.
Some Zelink fanfictions might explore an alternate timeline. In this timeline, Link and Zelda's relationship develops differently. They could start as childhood friends who have a premonition of the great challenges ahead, and their relationship evolves in a more gradual and complex way as they grow up.
One plot idea could be Naruto using his newfound time - stopping ability to prevent a major disaster in Konoha. For example, he could stop time just as a powerful enemy's ultimate attack is about to hit the village, and then find a way to counter it while time is frozen. Another idea is that Naruto uses it to have some peaceful moments with his friends and family that are always cut short in the normal flow of time. He could share a meal with his dad, Minato, and have a long conversation that was never possible before.