One idea could be Naruto discovers a hidden ancient jutsu that unlocks his ultra instinct - like powers. He then uses these powers to quickly defeat enemies in the Fourth Great Ninja War, surprising everyone including Sasuke. Another could be Naruto training in a secret dimension where he gradually attains ultra instinct and has to face off against a new, powerful and unknown enemy that threatens the entire ninja world.
A common plot point is Naruto's initial struggle to control the ultra instinct. It's not easy for him to harness this new power, and we see him face setbacks and challenges in the fanfiction. For example, he might accidentally use it at the wrong time or struggle to maintain it during a fight.
One idea could be exploring how Goku further masters Ultra Instinct in ways that are different from the canon. For example, he might have to face an enemy that can nullify his normal Ultra Instinct attacks, so he has to find new ways to use it, like combining it with Kaioken.
A plot could involve a mysterious figure from another dimension arriving in the RWBY universe with Ultra Instinct abilities. This figure could either be an ally or an enemy. If an ally, they could teach the RWBY characters how to access this power. If an enemy, the RWBY team would have to figure out how to counter this seemingly invincible ability. Also, perhaps there could be a side - story where a non - combatant character in RWBY, like a mechanic or a strategist, plays a crucial role in helping a fighter understand and use Ultra Instinct.
One idea could be an Ultra Instinct Goku crossing over with the Dragon Ball Super universe and the Naruto universe. He could end up in Konoha and use his Ultra Instinct to sense and counter the attacks of the ninja there. Maybe he'd even have to fight some of the powerful ninjas like Naruto or Sasuke in a friendly sparring match to test their skills against his new form.
Maybe Goku gets mixed up in the events of the Injustice storyline. He could initially be confused by the alternate version of Superman who has gone bad. Goku, with his pure heart and Ultra Instinct, might try to bring the corrupted Superman back to the light. This could lead to some intense battles with the Injustice League as Goku tries to set things right.
A plot could involve a group of rogue ninjas with a killer instinct forming an alliance. They target the Hidden Leaf Village with a plan to steal a powerful, ancient artifact. Naruto and his team have to not only stop them but also figure out the true motives behind this alliance. Along the way, they discover secrets about the artifact that could change the balance of power in the ninja world.
One possible plot development could be Goku struggling to control the Ultra Instinct state for an extended period. This might lead to him accidentally causing damage to his surroundings or even to his friends while in this super - powered state. Another could be that enemies take advantage of his 'stuck' situation, seeing it as a vulnerability to attack him when he can't fully regulate his power.
Another challenge is adapting his fighting style. Naruto's existing fighting style is based on his ninja training and the use of chakra. Ultra Instinct is a completely different concept. He has to figure out how to integrate the new power into his attacks and movements without losing his own identity as a ninja. For instance, he can't just abandon his signature Rasengan, but needs to find a way to use it in conjunction with Ultra Instinct abilities.
There are indeed Naruto fanfictions where he has Ultra Instinct. Fanfiction writers like to experiment with different power combinations. By giving Naruto Ultra Instinct, they can create really exciting battle scenes. For example, Naruto could use Ultra Instinct to dodge attacks more effectively during a fight with a powerful enemy like Madara, adding a whole new dimension to the story.
In 'naruto animal instinct fanfiction', there might be the concept of characters taking on animal traits physically. Like some characters could grow claws or have fur in certain situations for added protection or attack power. Also, the communication with animals could be a big part. Naruto could communicate with all kinds of animals in the forest, getting valuable information from them. And perhaps there are stories where the characters' emotions are more in tune with animal instincts, so they become more ferocious when angry or more cautious when sensing danger, just like animals in the wild.