It's difficult to know for sure. While the Harry Potter fanfiction world is huge and full of all kinds of creative and strange ideas, this specific combination of Harry Potter singing about monsters might not be common. However, with the popularity of exploring different scenarios in fanfiction, it wouldn't be a total surprise if there was at least one out there. You would probably have to search through various fanfiction platforms to find out.
One great Deku Monster Girls fanfic could be one where Deku discovers a hidden world of monster girls and has to learn their ways to save them from a common threat. Maybe he uses his quirk in unique ways to protect the monster girls and their habitats.
It could be a very strange and creative concept. Maybe it's about a scenario in a fanfiction where Harry Potter, in a completely out - of - the - box situation, starts singing about monsters. It might be a humorous or dark take on the Harry Potter universe, with the author of the fanfiction exploring new and unexpected aspects of the character.
It could be Orochimaru. He might see Naruto's 'monster - like' state as an opportunity to use him for his own experiments. Orochimaru has always been interested in power and Naruto's new, strange form could be a source of great power that he wants to harness for his evil plans.
Kakashi would be the most perceptive. He'd see how Naruto singing 'Monster' is not just a random act but a way for Naruto to connect with his own fears and insecurities. His friends from the Hidden Leaf Village would overall be proud of Naruto for trying something new and for using the song to share a part of himself that they may not have fully understood before.
First, think about the setting. Decide if it's in the existing My Hero Academia world or a new one. Then, create unique monster girl characters with their own personalities and powers. For example, a fire - breathing dragon - like monster girl. Next, plan out Deku's role. Will he be the protector, the learner, or something else? Finally, start writing the story with a clear plotline.
The main differences are in their expressions and some minor details of personality. In the manga, Deku might seem a bit more intense, while in the anime, he's sometimes presented a bit softer.
Deku might be completely shocked at first. Since Bakugou has always been so aggressive towards him, he would never expect such a confession. He might just stand there, mouth agape, not knowing what to say.
His friends could come to the rescue. Bakugo, for instance, might use his explosive power to break into Toga's hideout. He's always been competitive with Deku, but he also cares about him deeply.
In 'deku meets future deku fanfiction', perhaps the future Deku warns the present one about upcoming threats. He could tell him about villains he'll face in the future and how to defeat them. This would give the present Deku an edge in his battles and also in his growth as a hero.