Another theme is the idea of heroism. Both shows revolve around heroes. Fanfictions might focus on how Ben 10, with his alien forms, would be perceived as a hero in the 'Boku no Hero Academia' world, or vice versa. For example, a fanfic could show Ben 10 using his powers to save UA students from a new threat. It also delves into what it really means to be a hero in different contexts.
One great 'Ben 10' and 'Boku no Hero Academia' fanfiction is 'Ben in the Hero World'. It combines the unique powers of Ben 10 with the hero society of 'Boku no Hero Academia' in an interesting way.
The Boku no Hero manga is finished. It reached its conclusion after a successful run, leaving fans with a complete narrative and memories of an exciting journey.
Well, 'boku no hero novel' is probably about the adventures in the world of heroes. It could have new storylines that didn't make it into the main anime or manga. It may focus on a particular character's growth, like Midoriya's journey in a different light, or introduce new characters and their unique quirks within the hero - filled universe.
One popular idea could be creating an alternate origin story for a character. For example, giving Deku a different quirk acquisition experience that still leads to his growth as a hero.
It could be Midoriya. Imagine Midoriya getting access to Iron Man's technology. He's already a determined and intelligent hero - in - training, and with Iron Man's tech, he could become even more powerful. He might struggle at first to adapt to the new technology, but his strong will would drive him to master it and use it to protect others in new and exciting ways.
A cool plot could be that a villain in the Boku no hero world steals Iron Man's technology and starts creating chaos. The heroes then have to figure out how to stop the villain while also dealing with the unfamiliar technology. Or perhaps a young inventor in the Boku no hero world idolizes Iron Man and tries to recreate his suits, but with a twist related to quirks. This could lead to a story about the young inventor's journey, from being an unknown to becoming a key figure in fighting crime with their unique Iron Man - inspired creations.