Well, in many Harry Potter AU fanfictions, travel to an alternate universe can happen due to a disruption in time. If a time - turner is misused or there's a major magical event that messes with the time - space continuum, it can lead to an AU. Also, some fanfictions depict that a character's strong emotions and desires can trigger a journey to an AU. Say a character has a deep longing to see how things could have been different, and their magic responds by sending them to an AU. It's all very creative and varies from one fanfiction to another.
In AU 4th - year fanfictions, relationships can change a great deal. For example, if Harry was raised by Sirius instead of the Dursleys. His confidence might be higher, and his relationship with Draco could be less antagonistic from the start. Maybe they could even become reluctant allies in the face of a new threat at Hogwarts. Also, Hermione might form a closer bond with Neville as they study together more often in this AU, and Ron could become a bit jealous of their newfound friendship.
Common characters he could meet include an au Ginny who is a powerful seer. There might be a Hagrid who is a tiny, timid man instead of the large, boisterous one we know. He could also encounter an au Sirius Black who is a Death Eater, which would be a shocking twist. Additionally, he may run into an au Professor McGonagall who is more of an artist than a Transfiguration teacher.
If Harry Potter was in the Marvel Universe, he'd probably end up at Xavier's School for Gifted Youngsters. Think about it, a school full of mutants with special powers, and here comes Harry with his wizardry. He'd either be a great asset or cause a bit of a stir. His magical abilities would be a new kind of power that the X - Men and other mutants might not be used to dealing with.
One interesting plotline could be that in the alternate universe (au), Harry Potter discovers a world where magic is used in completely different ways. For example, instead of using wands, they use amulets. Another could be that he finds himself in a world where Voldemort won the war in his own universe, and he has to figure out how to change things in this au. Or perhaps he travels to an au where Hogwarts is a school for all magical creatures, not just witches and wizards.
Love is a very common theme. Since they are a couple in the original series, in the au fanfictions, their love often has to overcome new obstacles in the different universes created by the authors. For example, they might be from different magical houses with long - standing rivalries.
Well, in AU Harry Potter fanfiction related to traveling, you might encounter unique magical creatures that don't exist in the original universe. These could range from friendly, helpful beasts to terrifying and dangerous ones. The social structure of the wizarding world could also be different. There could be new political systems or different ways that pure - bloods, half - bloods, and Muggle - borns interact. And don't forget about the magic items. There could be new, powerful artifacts that drive the story forward, or existing ones with different properties or backstories.
Luna Lovegood might also be a possible love interest. Her unique personality and view of the wizarding world could attract Harry in a different way. She's not afraid to be herself and is very open - minded. In an AU, Harry could see her in a new light and they could start a relationship based on their shared experiences of being a bit different from the norm in Hogwarts.
Obviously, Harry could still be a main character. He'd be the brave new kid in high school, trying to make friends and figure out his place. Hermione would also be there, the super - smart girl who is always acing her classes and getting involved in every club. Ron could be Harry's best friend, the laid - back but loyal guy. And Draco could be the rich, snobby kid from the 'popular' group who constantly gives Harry a hard time.