It could be an alternate version of Dumbledore. Maybe in this dimension, he was corrupted by power. He uses his vast knowledge and influence to control the wizarding world for his own ends. He manipulates the students at Hogwarts and uses dark magic in secret while maintaining a public facade of being a great wizard.
One idea could be that in the alternate dimension, Voldemort won the war long ago. Hogwarts is now a dark and dreary place, with Death Eaters as teachers. Harry and his friends, who are part of an underground resistance, have to find a way to travel back in time to change the course of history.
In an alternate dimension fanfiction, Neville Longbottom could take center stage. He could be the hero who rises up against the dark forces. Luna Lovegood might also be a main character, with her unique perspective on the alternate wizarding world. And we could also have new characters that are exclusive to this alternate dimension. For example, a Muggle - born wizard who has the power to control time, and he teams up with Harry and his friends to save the wizarding world from a new threat that emerged in this alternate reality.
One idea could be that in the alternate dimension, Voldemort won the war and Hogwarts is now a dark and dreary place where students are taught only dark magic. Another could be that the wizarding world is merged with the Muggle world in a strange way, like there are magical creatures running amok in London streets. Or perhaps in this alternate dimension, Harry was sorted into Slytherin and has to deal with a whole different set of challenges and prejudices.
Well, in Harry Potter fanfiction, the 'Dimension Father' might be a character with a very specific role. Maybe he's a sort of guardian of the dimensional boundaries. He ensures that no dark magic from other dimensions seeps into the main Harry Potter universe. He could also be a source of knowledge for characters like Hermione who are always eager to learn new magic. For instance, he might teach her about the spells and incantations that are unique to other dimensions, which she could then use to help Harry in his fight against the dark forces.
A father in a Harry Potter fanfic could also be an educator. He could teach his children about the wizarding world, its history, and magic spells. He might pass on family - specific magical knowledge that has been passed down through generations.
In these fanfics, the theme of adaptation is quite common. Harry has to adapt to his new identity, whether it's a new name, a new magical ability, or a new social standing. Another theme is the exploration of different magical cultures. If his identity is changed in a way that he's associated with a different group, like a foreign wizarding community, it delves into different magical practices. And identity crisis is also a key theme. Harry may struggle with who he is now compared to who he was supposed to be in the original story.
She might encounter strange creatures. For example, in many alternate dimension stories, there are unique beings that don't exist in our world. Maybe she'll meet a talking animal or a floating jelly - like entity.
The dimension could be related to the father's past. For instance, he was accidentally sent to a parallel dimension as a child and had to find his way back. Now, he uses his experiences there to help his family face challenges in the regular wizarding world. He might teach his kids unique spells or ways of thinking that he learned in that other dimension.
In Harry Potter fanfiction, the dimension can be portrayed in various ways. Sometimes it's a parallel magical world with different rules. For example, a dimension where dark magic is the norm instead of being shunned. It can also be a place where time moves differently, like a dimension where a day in the regular Harry Potter world is a year there.