One popular 'deaged Naruto fanfiction' is 'Naruto: Reborn as a Baby'. It shows Naruto having to deal with his new situation while still possessing his old memories. Another one could be 'Deaged Naruto: A New Beginning' which focuses on how the village reacts to a younger Naruto and how he changes the future.
In some Naruto deaged fanfictions, the plot focuses on how the village reacts to a deaged Naruto. Since he's already a well - known hero in his original age, seeing him as a child again might make some people underestimate him. However, Naruto, with his unwavering spirit, still manages to prove himself in different ways, like showing off his ninja skills that he retained even in his deaged form.
In 'deaged Naruto fanfiction', usually Naruto is somehow magically or through some strange jutsu deaged. For example, he could be turned into a baby or a young child. Then the story explores how he copes with this new state.
Fanfiction.net is a great platform to start. It has a large collection of Naruto deaged fanfictions. You can easily search for the specific tag 'Naruto deaged' and browse through various stories. There are stories of different lengths and quality levels there.
One character that would be really interesting to pair with deaged Loki is Doctor Strange. Strange could be the one to help Loki figure out how to reverse the deaging process or use his new situation to his advantage. Also, if we consider the Avengers, Natasha Romanoff could be paired with deaged Loki. She could teach him some skills that he might not have learned in his original upbringing, like stealth and espionage. And Steve Rogers could also be a good match. Rogers' sense of honor and justice could have an impact on deaged Loki and maybe even inspire him to be a better person.
At first, Batman would be shocked and a bit confused. But quickly, his detective instincts would kick in. He would view the deaged Joker as a new and unexpected threat. He'd start gathering information about how the deaging occurred, in case it was part of a larger, more sinister plan. Batman would also be very careful not to underestimate the deaged Joker. He might try to isolate the Joker in a secure location to prevent him from causing chaos in Gotham. And he'd be constantly on the lookout for any signs of the Joker's old, devious self emerging from this new, younger form.
Weiss would probably be very protective at first. She has always had a bit of a mother - hen side to her, and seeing Ruby in a more vulnerable, deaged state would bring that out. She would likely try to keep Ruby out of trouble and make sure she was taking care of herself.
Well, a lot of 'deaged Hermione' fanfics have the theme of redemption. It could be that in her older self, she made some mistakes that she now has the chance to correct in her deaged state. And of course, the theme of mystery is there too. How she got deaged and what the consequences will be are often elements of mystery in these stories.
Time - related themes are quite common too. Sometimes the deaging is linked to time - travel, and this can lead to themes of changing the past or understanding the importance of events in a new way. There can also be a theme of growing up again, but in a different way this time. Harry might learn things he missed the first time around while growing up, and this new growth process can be a central theme in many deaged Harry fanfictions.
One popular idea in such fanfiction could be Sirius Black being deaged and having to adapt to the modern wizarding world. He might struggle with new spells and technology while still having his old memories.