I'm not entirely sure if there's a specific 'Naruto father of Katsuki Bakugou' fanfiction. There are so many fan-created works on the internet that it's hard to keep track of them all. It could be a really interesting concept though. Naruto has his own set of values and abilities from the Naruto universe, and Bakugou has his distinct personality in My Hero Academia. Combining them in a father - son relationship could lead to some really unique storylines, like Naruto teaching Bakugou some ninja techniques and how that would influence Bakugou's hero training.
One possible plot could be that Ochaco wakes up one day as a kid and has to figure out how to reverse it while also dealing with her now child - like body. She might struggle with her hero training as a kid, like not being able to reach high places or lift heavy objects like before. And she could have cute interactions with her classmates who are now much bigger and older - looking compared to her.
Bakugou in lemon fanfiction usually retains his explosive nature, but it can be channelled in different ways. For example, his determination might be shown in his pursuit of a romantic interest. He may also be portrayed as having a softer side that only a few get to see, especially in more intimate moments within the fanfiction.
One common theme is the development of an unexpected friendship. Given their different personalities in the original series, fanfiction often explores how they can bridge the gap and become friends or at least respect each other more.
Often, in 'uraraka x bakugou fanfic', there is a lot of emotional growth. Bakugou might learn to control his temper better because of Uraraka, and Uraraka might become more confident in herself. The fanfic uses their relationship as a vehicle for personal development for both characters.
Yes, there might be some out there. You can check fanfiction websites like Archive of Our Own (AO3). There are a large number of fan - created stories in the My Hero Academia fandom, and it's possible to find one with this particular pairing and plot. Just use the search function on the website and type in relevant keywords like 'Bakugou x Uraraka pregnant' to narrow down your search.
One common theme is friendship. Many fanfics explore how Bakugou and Uraraka can form an unlikely friendship. Despite their different personalities, they find common ground and support each other's growth as heroes.
Mentally, Ochaco would struggle. She has the mind of an older person but is trapped in a child's body. She would have to deal with the frustration of not being able to communicate as effectively as she used to. And she might feel a sense of loss for her normal life and the progress she had made in her hero training and relationships.
The plot could be about Bakugou getting exposed to some sort of gamma - like radiation that gives him Hulk - like powers. He then has to figure out how to control it while still being himself. Maybe he accidentally destroys some things around him at first, and has to face the consequences. Along the way, he could team up with his friends to fight against villains who are now even more afraid of this new, super - powerful Bakugou.
No, it is not appropriate. Writing fanfic that involves nudity in a sexualized way about a character is unethical and violates the boundaries of respect for the character and the source material. It also may not be suitable for a general audience and can make others uncomfortable.