Well, perhaps the Truth - Seeking Ball is a gift from some long - forgotten deity in the Naruto fanfiction. Naruto then has to figure out how to integrate it into his combat style. Since the Truth - Seeking Ball has such unique and powerful abilities, like being able to nullify jutsu, Naruto could use it to gain an upper hand against the Akatsuki members who are still causing trouble. He might also face challenges from other ninja villages who are jealous of his new power and want to steal the Truth - Seeking Ball for themselves.
Maybe there is a villain who is trying to collect powerful artifacts from different universes, and the truth - seeking orbs are on their list. Velvet gets involved when she accidentally stumbles upon the orbs. She then has to protect them, and in the process, she learns how to use their power. She teams up with some Naruto characters who also want to stop the villain, and together they form an unlikely alliance to save both their worlds.
Power is a common theme. The truth seeking balls are extremely powerful in the Naruto universe, so fanfics often explore how characters gain, control, or are corrupted by this power.
One possible plot could be that Naruto discovers a hidden power within himself that unlocks the Rinnegan. This new power could make him face new and even more powerful enemies. He might have to learn to control the Rinnegan's abilities, which are different from his normal chakra powers. For example, the Rinnegan can allow for space - time manipulation. Naruto would struggle at first, but with the help of his friends, he would gradually master it and use it to protect the Hidden Leaf Village from a new threat that only the Rinnegan - powered Naruto can defeat.
Perhaps in the fanfiction, the pacifier is a magical item. It could be that Naruto discovers the pacifier and when he uses it, he gains some sort of unique power. For example, it might allow him to communicate with animals in a new way or give him enhanced strength but only when the pacifier is in his mouth. This would lead to some interesting situations where he has to keep the pacifier safe while using its power to fight enemies.
Well, perhaps in this fanfiction, Naruto acquires Kamui due to some sort of strange chakra experiment gone wrong. And then he has to learn to control it quickly. He could start by training with Kakashi, who has experience with Kamui. Together they figure out new ways to combine Naruto's regular jutsu with the Kamui ability, like making a Rasengan that can be teleported right into the enemy's chest using Kamui.
Well, perhaps the story could revolve around a tournament. Naruto, with his Hercules strength, enters this grand tournament. He has to face opponents who are also extremely powerful. His strength gives him an edge, but he also has to learn to control it. Along the way, he meets new allies and they all have different motives related to the tournament.
The plot could be about Naruto's little brother growing up in Naruto's shadow. He might struggle to find his own identity while constantly being compared to Naruto. Maybe he has different ninja abilities that are overlooked at first because everyone is so focused on Naruto's power.
One possible plot could be that Naruto discovers he has a Byakugan eye through some strange encounter or experiment gone wrong. This new power could initially be a source of confusion for him as he tries to figure out how to control it. He might seek out the Hyuga clan for help, and there could be a whole arc about him learning the ways of the Byakugan while still maintaining his own unique ninja style.
The plot could involve Naruto being sent to an alternate dimension where the blue Rinnegan is a common power among a group of powerful beings. There, he has to learn to use his blue Rinnegan to survive and also to find a way back home. Along the way, he meets different characters who teach him unique ways to harness the power of the blue Rinnegan, and he returns to his world with new skills and knowledge.
One possible plot could be that Naruto discovers a special face mask with hidden powers. For example, it might enhance his senses when he wears it, allowing him to detect enemies from a greater distance. This could lead to new adventures as he has to figure out how to control and use these new powers while still being himself.