Create a unique setting for the hypnosis. Instead of the usual Hogwarts, it could be in an ancient, long - forgotten wizarding temple. The new environment adds mystery and adventure to the fanfiction.
Add complex characters. For example, introduce a new villain who is behind the hypnosis and has a deep backstory. This gives more depth to the plot.
In this type of fanfiction, there could be a plot where Harry is hypnotized during a Quidditch match. The opposing team might have used some dark magic to hypnotize him so that he would lose the match. However, his broomstick, which has a special bond with him, could start to resist the hypnosis on its own. Meanwhile, his teammates realize something is wrong and try to protect him from further harm while also looking for a way to break the spell.
Involving other characters in an interesting way can make it more engaging. Maybe there's a character who is trying to understand what the baby is experiencing during hypnosis. They could be an older sibling or a parent. Their reactions and attempts to communicate with the baby can add depth to the story. Also, creating a sense of mystery around the hypnosis itself, like not revealing all at once why the baby was hypnotized or what the full extent of its effects are, can keep the readers hooked.
One idea could be a character in a fantasy world being hypnotized by an evil sorcerer and their friends having to break the spell. Another could be a modern - day detective being hypnotized to recall a crucial clue in a case. Or perhaps a superhero being hypnotized by a villain to fight against their own team.
Most of the official 'Harry Potter' works don't have such themes. Fanfictions with this kind of rather strange combination might be a very niche area. Maybe some independent authors are exploring such concepts in their own creative ways. But it could also be that very few exist due to the odd nature of the combination.
To make a Harry and Snape detention fanfiction interesting, you can focus on their character development. For example, show Snape's internal struggle between his dislike for Harry based on his past with James and his duty as a teacher. For Harry, explore his growing understanding of the adult world and how Snape fits into it. Also, add some mystery elements like a hidden potion ingredient that they discover during the detention.
One way to make it interesting is to focus on the clash of their powers. Harry's magic is based on spells and potions, while Hela has her own set of god - like abilities. Their interactions in a battle or a situation where they need to cooperate could be exciting.
One interesting 'naruto hypnotized fanfiction' story could be about Naruto being hypnotized to forget his ninja skills and having to relearn them in a unique way. Maybe a villain uses a new type of jutsu to hypnotize him, and his friends have to figure out how to break the spell.
Another type could be in a mystery or detective - like scenario. The male reader is hypnotized as part of an investigation, and through his hypnotized state, he reveals crucial clues that help solve the case. This adds an interesting twist to the traditional mystery plot.
One interesting idea could be the unique way the baby's perception is shown while hypnotized. Maybe the baby has extraordinary dreams or visions that are not possible in a normal state.
To make it interesting, you could focus on the clash of different power systems. Supergirl's super strength and flight against the magic of Harry Potter. And use the lemon as a unique element, like a lemon - scented spell that only Supergirl can smell and it leads her to a hidden part of Hogwarts. This kind of unique combination of elements can draw readers in.