Petunia will be nicer and will not hate Harry
Vernon will be dumb like extremely dumb.
Duddly will be a girl named Sally.
Sally is adopted.
Harry would not be abuseing harry.
Harry is a shapeshifter.
Now i concidering Harry mentally 27 years old for my convinience.
All physical ages are same as cannon.
Harry has no physical age his body can chage at will so he is ageless.
I am writing from Harry's perspective.
Its a harem fanfiction.
Harry will be powerful godlike powerful