Perhaps Rose is a mysterious child with a prophecy attached to her. The wizarding world is on edge about her existence, but Harry, believing in the good in people, adopts her to protect her from those who would use the prophecy for their own evil ends. He becomes her protector and mentor, guiding her through a world full of secrets and danger.
In a 'harry adopts rose fanfiction', perhaps Rose has some special power or connection that draws Harry to her. Harry might adopt her to keep her safe from those who would misuse her power. He then has to navigate the challenges of being a single parent in the wizarding world, like getting her enrolled in Hogwarts, dealing with other parents who might be suspicious of his motives, and helping Rose control her magic as she grows up.
Maybe some of Draco's old Slytherin friends or acquaintances make an appearance. They could either support or oppose Draco's decision to adopt Rose, depending on their own views and how they've changed since their school days.
There could be a little fairy who is friends with the rose. The fairy could help the beast understand the language of the plants in the garden where the rose is, so that he can better communicate with the rose.
There could be a mysterious wizard. This wizard might be the one who sets the miracle in motion for Rose. He could be an old and wise figure, guiding Rose through the strange new experiences that come with the miracle.
Another interesting plot could be Rose's discovery of Draco's past and how she helps him come to terms with it. She might find out about his family's dark history during the wizarding wars and be a source of light and forgiveness for him.
It's hard to say who the 'best' are, but there are some well - known names in the fanfiction community. Some authors who have a large following often create really engaging storylines that stay true to the essence of the Potter universe while adding their own unique twists with Harry and Rose Potter.
They could be in a time - travel scenario. Harry Potter accidentally takes Rose and Dobby back in time. They have to work together to get back to their own time. Dobby's house - elf magic might be crucial in finding a way back, while Rose uses her modern - day knowledge of magic (maybe she's read a lot about old magic) to help them along, and Harry Potter uses his experience from his own adventures.
I don't know who created 'harry the rose fanfic'. There are so many fanfic authors out there, and without more information, it's impossible to tell.
Maybe an artist could be the main character. He is drawn to the beauty of a blooming rose and uses it as his inspiration. Through his art, he tries to capture the essence of the rose, and in the process, he discovers things about himself and the world around him.
It could be a young wizard who lost their parents during the final battle against Voldemort. Harry feels responsible for all the orphans created by the war and decides to take this particular child under his wing.