In this fanfiction, Harry Potter would interact with the Queen in a very unique way. Since he is used to the hierarchical system in Hogwarts, he would understand the importance of showing deference to the Queen. He could offer her a magical gift, like a charm that gives good luck. And the Queen, being curious, might ask him about his world. Harry would have to be careful not to reveal too much about the wizarding world to the muggles, but still satisfy her curiosity. There could be some misunderstandings too, for example, when Harry tries to explain some magic concepts using wizarding terms that the Queen doesn't understand.
Well, he might be quite astonished by the grandeur of the Queen's palace. Maybe he'd try to use his magic subtly, but end up causing some minor chaos, like making the guards' hats fly off accidentally.
Perhaps Harry Potter is summoned to Queen Elizabeth's court by a dark wizard who wants to use Harry's fame to gain power. Harry has to find a way to escape this situation and also protect the queen from the dark wizard's plans. He might use his knowledge of magic and his Gryffindor courage to outwit the dark wizard and return to his own time, leaving behind a legend in Queen Elizabeth's court.
Harry would likely be very curious about the court and its people. He might use his magic in small, discreet ways to amuse the courtiers, like making a flower bloom in his hand. He would probably be polite and respectful, but also a bit of an outsider. His different style of dress and his magic would make him stand out, and he'd have to explain himself carefully to avoid being seen as a threat.
Well, Harry could be really confused at first. Ouran is a very different world from Hogwarts. He might be shocked by the opulence of Ouran Academy and the strange club system there. Maybe he'd try to find a way to fit in while still being true to his wizard self.
Well, it could be that the Queen has a special connection to the wizarding world in this fanfiction. Perhaps she has been secretly informed of Harry's bravery and selflessness all along. And as a symbol of the British monarchy, she knights him to show that the Muggle and wizarding worlds can have a positive relationship. So, she bestows this honor on Harry.
It could be an original character created specifically for the fanfiction. A young and beautiful queen of a small, yet prosperous kingdom, who has a strong will and a love for her people. She might be open - minded and curious about the wizarding world, which makes her a perfect match for Harry.
It might be an ancient magical being that has the form of a queen. She could have ties to the very origins of magic in the Harry Potter universe and decides to save Harry because she foresees his importance in the future of magic. For example, she could be a guardian of some sort of magic that is crucial for Harry to defeat Voldemort in the long run.
It could be the Queen of England, as in the real - world monarchy. In the fanfiction, she might be a figure with hidden knowledge of the wizarding world and decides to use her power to rescue Harry.