A possible fanfiction is one where Lady Hela is a time - traveling character who ends up in the 'Harry Potter' universe during the time of Voldemort's rise. She could either help or hinder Harry's fight against Voldemort, depending on her motives. Her knowledge from her own realm could be used to either save or destroy the wizarding world.
One popular Harry Potter fanfiction might be those that explore alternate universes, like 'The Veil's Echo' which imagines a world where Voldemort won the Battle of Hogwarts and the characters have to fight in a very different kind of resistance. Another could be the story 'Muggle - Born Magic' which delves deeper into the experiences of muggle - born witches and wizards in a more detailed and unique way compared to the original books. And then there's 'The Time - Twisted Trio' that plays with the idea of time travel and how it could change the events and relationships in the Harry Potter universe.
One idea could be that Hela somehow ends up in the wizarding world. She might be intrigued by the magic there which is different from her own powers. Maybe she tries to take over Hogwarts, thinking it's a place of great power. Another could be that Harry Potter has to team up with Hela to defeat a common enemy that threatens both the wizarding world and Asgard.
Dumbledore and Lady Hela would be an interesting combination. Dumbledore's wisdom and Hela's power could lead to some intense and thought - provoking interactions. They could be on opposing sides at first, but then find common ground in their goals for the wizarding world.
One idea could be that Harry discovers his true mother is Hela and has to deal with the new identity. He might face discrimination from some in the wizarding world who fear Hela's reputation. Another could be that he inherits some of Hela's powers, like the ability to control the dead in a more magical way than normal necromancy in the Harry Potter universe.
One interesting aspect could be new magical creatures introduced in such fanfictions. Maybe there are unique interpretations of the Lady of the Lake within the Harry Potter universe. For example, she could have a special connection to the Forbidden Forest and its secrets.
One way to make it interesting is to focus on the clash of their powers. Harry's magic is based on spells and potions, while Hela has her own set of god - like abilities. Their interactions in a battle or a situation where they need to cooperate could be exciting.
Hela would likely be more powerful. She is a goddess in the Marvel universe with superhuman strength, the ability to summon weapons, and immortality. Harry Potter, while very powerful in the wizarding world, has limits to his magic. His spells and abilities are mainly within the realm of magic that wizards understand. Hela's powers seem more raw and on a much larger scale compared to Harry's.
Another one is 'A Black Comedy in Three Acts'. It focuses on different characters' perspectives and how they interact within the complex world of Hogwarts. It has some really engaging plotlines that keep readers hooked.
One interesting aspect could be the crossover of magic systems. Since Harry Potter has its own complex magic world and Lady Sif comes from the Norse mythology - inspired world of Thor in Marvel. In such fanfiction, perhaps they might combine spells from Hogwarts with the Asgardian magic or combat skills. For example, a story could have Harry teaching Lady Sif some transfiguration spells and in return, Lady Sif showing Harry how to fight with an Asgardian sword in a more effective way. However, it's important to note that not all fanfictions are well - written, and some might deviate too much from the original characters' personalities.
It's hard to say precisely without reading it. But generally, in such a fanfiction, Harry Potter would be in a very different and probably challenging situation as the master of Hela. It could be that he has to navigate the politics and power struggles in a world related to Hela. He may also have to face enemies who are after Hela's power or want to oppose Harry's new role.