A common theme is the connection to the past. Since Ashura is from an ancient time in the Naruto universe, many fanfics explore how his story links to the present day events in the series.
Power inheritance is another theme. Fanfics often deal with how Ashura's power might be passed down or reawakened in new characters, and how that changes the power dynamics in the Naruto world. It can lead to really intense storylines where characters have to learn to control this new - found or ancient power.
One common theme is the struggle between power and peace. Indra was often power - hungry while Ashura was more about peace. Another theme is the idea of destiny and reincarnation. Since they are reincarnations in the Naruto lore. And family ties also play a big role as they are brothers.
A fanfic could explore what if Naruto and Sasuke were fully aware of their Indra and Ashura identities from the start. Maybe they are born with memories of their past lives. This would completely change their relationship dynamic. They could be more united from the beginning, working together to reform the ninja world according to the will of their predecessors. They might introduce new jutsu and ninja teachings based on the ancient knowledge of Indra and Ashura, which would face opposition from the traditional ninja clans who are resistant to change.
A frequent theme is 'Time - Travel'. In these fanfics, a character, often Naruto, travels back in time and tries to change the past. This allows for a whole new set of adventures and interactions. Another common theme is 'The Ninja World's Politics'. Fanfic writers explore how the different hidden villages interact, form alliances, and compete for power in more detail than in the original series.
The power dynamics between them. Since Indra was known for his power and Sasuke has always been a strong character, and Naruto as Ashura is also very powerful. Their battles and how they balance each other's powers would be important. For example, when they fight side by side, how they combine their different chakra natures and jutsu.
I'm not sure specifically what 'ashura yasha fanfic' is about as it could be very different depending on the creator. It might be a fan - made story that involves characters named Ashura and Yasha. It could be about their adventures, relationship, or some fictional events in a particular fictional universe.
One popular type of Ashura Naruto fanfiction might be those that explore Ashura's past and his connection to the Uzumaki clan. Maybe it delves into how his chakra influenced Naruto's own power development.
One common theme is friendship. Riolu often forms strong bonds with Naruto and other characters, just like in the original Naruto series where friendship is a major aspect.
One common theme is the exploration of their opposing beliefs. Naruto believes in protecting his friends and village, while Deidara has his own view on art and destruction. Fanfics often play with how these two views can clash or merge.
A prevalent theme is adventure. Writers like to send Naruto and Chichi on various adventures together. It could be a quest to find a lost artifact or to save a village. Also, the theme of understanding different cultures comes up. Given Naruto's world is diverse and Chichi has her own cultural background, fanfics may explore how they come to understand each other's cultures better. And of course, there's the theme of cooperation, as they work together to overcome challenges.
The theme of sacrifice is often present. In some fanfics, either Kakashi or Naruto is willing to sacrifice for the other, as in 'Sacrifice for a Comrade'. Also, the idea of self - discovery is common. Naruto discovers more about himself with Kakashi's help, and vice versa. 'Self - Discovery in the Ninja World' is a fanfic that shows this well. And finally, the theme of perseverance. Both characters are known for their perseverance, and fanfics like 'Persevering Together' highlight how they encourage each other to keep going in the face of difficulties.