Ariana Grande could be a guest lecturer at Hogwarts. She could teach the students about the power of music in the muggle world and how it can be related to magic. Harry could be skeptical at first but then realize there are similarities. They could also go on adventures together outside of Hogwarts, exploring the wizarding world and Ariana sharing her muggle experiences, which would be really interesting for Harry and his friends.
One way they could interact is if Ariana Grande is a transfer student from a different magical school. She could be sorted into a Hogwarts house, and Harry could be her guide, showing her around the castle. They could share their different magical experiences, with Ariana talking about her school's unique magic and Harry sharing about the threats they've faced at Hogwarts. They might also bond over their shared experiences of having to deal with fame in their respective worlds, Ariana in the muggle music industry and Harry as the Boy Who Lived.
Well, in some fanfictions, Ariana Grande might be a witch who uses her music to fight dark magic. For example, she could team up with Harry Potter to defeat a new dark wizard. Her songs could be turned into spells. Or perhaps she is a long - lost relative of a Hogwarts founder and she discovers her heritage while also dealing with her muggle - like fame in the wizarding world.
They could interact through a magical portal that connects their two worlds. For instance, Supergirl could be curious about the magic in Harry's world and visit Hogwarts. She might use her superpowers to help in a Quidditch match, like flying really fast to catch the Golden Snitch before any of the players. Harry, on the other hand, could visit Metropolis with Supergirl and be amazed by the tall buildings and advanced technology.
One way for them to interact is if a wizard from the Harry Potter world has a special interest in the magic of Mowgli's jungle. This wizard could send Harry on an expedition there. When Harry arrives, Mowgli sees him as a strange intruder at first. But as Harry shows his good intentions, they start to work together. Mowgli could introduce Harry to the different parts of the jungle, and Harry could share stories of his adventures at Hogwarts. As they spend more time together, they realize that they can help each other. For instance, Mowgli's animal friends could help Harry find a rare magical plant in the jungle, and Harry could use magic to protect the jungle from a group of poachers who are after some of the magical animals.
In a fanfiction, Puck could be a sort of guide for Harry in the Forbidden Forest. Harry is often in danger there, and Puck, with his knowledge of nature and magic, could help him navigate through the forest and avoid dangerous creatures. Also, Puck might introduce Harry to some magical creatures that are unique to his world.
They could interact as classmates at Hogwarts. McGee might be in the same year as Harry and they study together, help each other with homework, and get into adventures in the castle.
They could interact through a magical portal. For example, Mulan could be curious about the strange new world she enters through the portal and Harry could help her understand the wizarding world. He could introduce her to things like wands and spells.
Another way is through a friendly rivalry. Artemis, with his brilliant mind, could compete with Hermione or other intelligent characters in the Harry Potter world in areas like spell - making or magical theory. They could learn from each other's different ways of thinking, with Artemis bringing in scientific thinking and the Hogwarts students sharing their magical knowledge.
Matilda could be invited to Hogwarts as a special guest lecturer by Dumbledore, who has heard of her extraordinary abilities. Harry would be assigned to show her around the castle. As they walk through the corridors, they start discussing the similarities and differences between the magic in Hogwarts and Matilda's own powers. They might also compare the challenges they've faced in their respective worlds, like Harry against Voldemort and Matilda against her cruel parents and the headmistress of her school.
Ariana Grande adult fanfiction is generally not appropriate. Fanfiction should respect the artist's image and not involve inappropriate or unethical content. Ariana Grande is a public figure, and creating adult - themed fanfiction about her can be seen as disrespectful and invasive of her privacy.
Another fanfiction could be set in an alternate universe where all the characters from Victorious have superpowers. Ariana Grande's character discovers she has the power to control sound, which she uses both for good, like helping her friends in their performances, and for some comical mishaps when she can't control it properly.