Indra and Asura are also characters that are frequently paired with Hagoromo in fanfiction. These pairings often explore the family dynamics more closely, such as Hagoromo teaching them new skills or them helping Hagoromo in some way that was not shown in the original series.
One interesting concept could be exploring Hagoromo's early life in more detail. Maybe his relationship with his family members, like his mother or father, who are not much explored in the original series.
Saitama from One Punch Man would be an interesting pair. Saitama's simple yet overpowered nature could create an interesting dynamic with Hagoromo's complex and ancient powers.
One idea could be to cross Hagoromo Otsutsuki with a character from a different anime universe, like Goku from Dragon Ball. They could have a power - level comparison and then team up against a common enemy. Another plot could involve Hagoromo in a modern - day world crossover, where he has to adapt to new technology while still using his ancient powers.
In the fanfiction, Kaguya could start as a somewhat menacing figure but as she spends time with Hagoromo and Hamura, she begins to show her more vulnerable side. Hagoromo may develop his leadership skills as he tries to bridge the gap between Kaguya and Hamura. Hamura could develop his diplomatic skills as he has to deal with the complex relationship between the other two. Their character development would be shaped by the various conflicts and reconciliations they experience together.
One possible plot could be that Kaguya, before her fall into darkness, tries to teach Hagoromo and Hamura some of her unique jutsu. This could lead to a stronger bond between them and change the course of the events that later led to her downfall.
The abilities might be different too. Since Naruto has his own set of skills like the Rasengan and Sage Mode, his Susanoo could incorporate those elements. For example, his Susanoo's hands could form giant Rasengan - like attacks, or it could have the ability to enter Sage Mode, which would be a huge departure from the regular Uchiha Susanoo's abilities.
In fanfiction, the Perfect Susanoo is usually much larger and more powerful than the normal Susanoo. It might have additional limbs or weapons that the normal one doesn't have. For example, it could have extra arms to hold more weapons or perform multiple attacks simultaneously.
Well, in many fanfictions, Naruto might first awaken Susanoo during a really intense battle. Maybe he's pushed to his limits while fighting a super - strong enemy, and his latent Uchiha blood (if that's part of the fanfic's premise) gets activated, leading to the awakening of Susanoo.
Perhaps it could be another entity related to Hagoromo. If Naruto abandons Hagoromo, there might be a counterpart or a follower of Hagoromo who sees Naruto as a threat or a traitor. This person could then become the main antagonist, trying to either bring Naruto back to Hagoromo's side or simply eliminate him.