A possible plot could involve a Dragonborn who discovers a hidden portal to the wizarding world. In the wizarding world, they learn about magic wands and spells. The Dragonborn could then combine their Thu'um powers with magic spells to fight against dark forces that are threatening both worlds. For example, Voldemort could team up with Alduin in some way, and the Dragonborn and Harry Potter have to work together to stop them.
Perhaps in this fanfic, the Hogwarts School is transported to Skyrim. The students have to adapt to the new environment, while the Skyrim locals are both curious and a bit wary of these strange magic - users. The Gryffindor students might be eager to learn about the brave warriors in Skyrim, and the Skyrim warriors could be intrigued by the magic of the Hogwarts students. There could be a big battle where they all have to fight together against a common enemy like a powerful necromancer.
One idea could be Harry Potter arriving in Skyrim and using his magic to combat the dragons. Maybe he teams up with the local mages and they learn from each other's magical techniques.
Maybe Harry gets involved in the civil war in Skyrim. He could use his Hogwarts-taught dueling skills to fight in battles, and his knowledge of magic could be used to solve some of the political intrigues. He might also try to find a way to bring peace to Skyrim using his unique perspective on magic.
One idea could be that Hogwarts is magically transported to Skyrim. The students have to deal with the cold, the dragons, and the different magic systems. Another could be that Harry and his friends are sent on a quest in Skyrim to find a powerful magical artifact that could help defeat Voldemort. Maybe they have to team up with the Nords and learn their ways of fighting and magic.
Well, perhaps in the fanfic, the 'Harry Potter' actors are cursed to forget their real identities and believe they are the characters they played. So, Rupert Grint would think he is Ron Weasley and start causing all sorts of chaos in the Muggle world as he tries to find his way back to Hogwarts. Or, the actors could be invited to a special event at Hogwarts and end up having to perform a play about the events of the wizarding war, which could lead to some really interesting interactions with the characters who lived through it.
One idea could be that the actors from the Harry Potter movies get magically transported into the wizarding world of Harry Potter. They could use their knowledge of the story to help the characters, or they could be completely bewildered and cause chaos. For example, Daniel Radcliffe could end up having to explain to Harry Potter himself how his story is told in the Muggle world.
One idea could be that Harry Potter and his friends accidentally get transported to the RWBY world. They could then use their magic in unique ways to help the RWBY characters fight Grimm. For example, Hermione could use her knowledge of spells to create new defenses against the Grimm that the RWBY characters haven't thought of before.
One interesting concept could be the combination of magic systems. In Harry Potter, there's wand - based magic, while Skyrim has shouts and spellcasting in a different way. A fanfic might explore how wizards from Hogwarts would adapt to the magic in Skyrim, or vice versa. For example, a Hogwarts student trying to master a dragon shout.
One idea could be that Harry discovers Narcissa has a secret mission to undermine Voldemort from within. Maybe she's been secretly helping the Order of the Phoenix all along and Harry stumbles upon this knowledge.
In a 'Harry Potter meets Tom Riddle' fanfiction, a really unique plot could be that Tom Riddle is reborn as a normal wizard without the dark desires due to some powerful magic. Harry Potter meets this new Tom and they become friends at Hogwarts. However, there are still some remnants of the old Tom's power that attract dark forces. So, Harry and Tom have to work together to fend off these threats while also exploring Tom's new identity and how it affects the future of the wizarding world. This would involve a lot of character development for both Harry and Tom, as they navigate their relationship in this new scenario.
A plot could revolve around a magical artifact that has been stolen from Hogwarts. Harry and Pansy are the prime suspects in each other's eyes. But as they start to investigate, they realize they are being framed. They then team up to find the real thief. Along the way, they discover that they have more in common than they thought, like their love for Hogwarts in their own ways. As they search through the dark corners of the castle and the Forbidden Forest, their relationship evolves from animosity to respect.