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.
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 interesting crossover could be the fight styles. In 'Kengan Ashura', there are intense martial arts battles. When combined with 'Naruto', ninjutsu could be pitted against those martial arts. For example, Naruto's shadow clone jutsu against a Kengan fighter's unique combat techniques. It would be a battle of speed, strategy, and power.
Goku from Dragon Ball Z would be an interesting addition. His Saiyan powers and love for fighting would make for some epic battles against the Kengan Ashura fighters. His ability to transform and increase his power levels would pose a great challenge to them.
One idea could be a crossover with another fighting anime like Baki. The fighters from Kengan Ashura could face off against the strong characters in Baki. It would be exciting to see their different fighting styles clash.