One way is to make the Otsutsuki OC a hidden observer during the Uchiha massacre. They could be there to study the Sharingan or the power dynamics within the Uchiha clan. For example, they might be interested in how the Uchiha's emotions, like hatred, are related to the power of their eyes. Another way is to have the OC be a factor that somehow influences Itachi's decision. Maybe they offer him a different option or some knowledge that makes him rethink his actions, but in the end, the massacre still occurs due to the complex web of political and clan - related reasons in the Naruto universe.
The Otsutsuki OC might be an unexpected bystander during the Uchiha Massacre. For example, they could have been on a different mission in Konoha when the massacre started. They might then decide to get involved, either to save some Uchihas out of a sense of justice or because they see potential in the Uchiha bloodline for their own purposes. So, they end up interfering with Itachi's plan and creating a whole new set of consequences for the story.
The Otsutsuki OC could be a catalyst. They might have some knowledge about the future or some power that the Uchiha want. This could lead to internal strife within the Uchiha clan as some members might be tempted to side with the OC for power, while others oppose it, which could be a contributing factor to the massacre.
Well, the OC might try to prevent the Uchiha Massacre. Maybe they have a different view of the Uchiha compared to the Konoha leadership. They could try to convince the Uchiha to flee or negotiate with Konoha. If they have unique powers or knowledge, they could use it to expose the real motives behind the planned massacre and create a situation where the Uchiha are spared. This would completely rewrite the story of the Uchiha's downfall.
One popular theme is the struggle between the Otsutsuki and Uchiha powers within the Naruto universe. The OC (original character) often has to navigate the complex politics and power dynamics of these two powerful clans. Another theme is redemption. For example, an OC Uchiha who has to overcome the dark past of the clan, like the massacre, and find a new path in the world filled with Otsutsuki threats. Also, themes of friendship and loyalty are common. The OC might form unlikely alliances with characters from different clans in order to face the common Otsutsuki enemy.
To create a compelling OC, start with their appearance. For this type of fanfiction, you could give them features that are a blend of the Uchiha and Otsutsuki. For example, the dark hair of the Uchiha but with the strange markings of the Otsutsuki. Then, focus on their goals. What do they want? Is it to bridge the gap between the two clans? Or to rise above them? Their relationships are also crucial. How do they interact with existing Naruto characters? Do they make friends easily or are they more of a loner? And don't forget about their weaknesses. A character with flaws is more relatable and interesting.
A fanfic could focus on Indra's training. We could write about the intense and arduous training he underwent to become such a powerful figure. It might involve secret techniques passed down in the Otsutsuki clan that only he was able to master due to his unique talent.
Another angle could be a fanfic where Indra Otsutsuki travels to a different dimension. He has to adapt to a completely new world with different rules and powers. It would be fascinating to see how his Otsutsuki abilities fare in this new environment and how he interacts with the local inhabitants.
Yes, there are likely some fanfictions with this concept. Fanfiction writers often come up with unique and creative ideas, and the idea of Naruto having some sort of special connection or relationship with Kaguya Otsutsuki in a fan - created story is not unheard of. It could involve Naruto exploring Kaguya's past, or perhaps having a role in her redemption in the fanfic's alternate universe.
Kaguya otsutsuki is often a very popular character. Since she was the progenitor of the otsutsuki in the Naruto canon, fanfictions like to explore more about her backstory and her relationship with other characters. Another popular one is Momoshiki otsutsuki. His powerful abilities and his encounter with Naruto in the series make him a great character to expand on in fanfiction.