Another concept could be a story where the power - enhancing techniques in Kengan Ashura are somehow related to the chakra system in Naruto. Maybe a character from Kengan Ashura discovers a way to tap into chakra, and Naruto characters have to deal with this new threat. This would involve a lot of world - building and exploring how the two different power systems interact.
When writing a Harry Potter and Yujiro Hanma fanfiction, it's important to establish the rules of the combined world early on. Will Yujiro be able to use magic? If not, how will he defend himself against magical attacks? You can also play with the idea of cultural differences. Yujiro comes from a very different kind of world compared to the wizarding world. This can lead to some interesting misunderstandings and comical situations. For instance, Yujiro might think the Sorting Hat is some kind of strange creature trying to attack him and try to fight it off. As you write, keep the pacing right, not too slow or too fast, and make sure the story has a satisfying ending, whether it's a happy ending or a more bittersweet one.
One interesting Yujiro Hanma fanfiction could be about his early days of training. It might explore how he developed his extreme strength and fighting skills. Maybe it shows his encounters with various opponents during his youth and how he overcame them to become the fearsome fighter he is known as.
To write a great Naruto Kengan Ashura fanfiction, you should also pay attention to the pacing. Don't rush through important events. Let the action scenes build up gradually. For instance, if there's a big fight between a Naruto character and a Kengan Ashura character, describe each move, the strategy behind it, and how the characters are feeling during the fight. Also, research any cultural or historical elements in both series that you can incorporate into your fanfiction to make it more rich and detailed. This can include things like the clans in Naruto or the different fighting styles in Kengan Ashura.
Many fanfics also feature Kanoh Agito. He has a mysterious air about him and his incredible fighting abilities make him a prime choice for fanfic writers. Himuro Ryo is also popular. His relationship with other characters and his own fighting style are often explored in fan - created works. And the new and upcoming characters also tend to gain popularity as fanfic writers like to expand on their potential stories.
Some fanfics might focus on the relationships between the fighters outside of the ring. Like how they interact in their daily lives, or form alliances or rivalries that are not directly related to fighting. There could also be concepts about new tournaments being created with different rules. This could change the whole dynamic of the Kengan Ashura world and force the fighters to adapt in new ways.
One possible plot could be a crossover where Yujiro Hanma somehow finds his way into the wizarding world of Harry Potter. Maybe he's on a quest for ultimate power and hears rumors of the powerful magic there. He could start challenging the most powerful wizards, like Dumbledore, thinking their magic is just another form of strength to be conquered.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). It has a large collection of fan - created works from various fandoms, including Yujiro Hanma fanfiction. Just use the search function and type in 'Yujiro Hanma' to see what's available.