There are fanfictions where Naruto's power is shown through his ability to connect with the spirits of past Hokages. With their combined wisdom and his own strength, he's able to perform a super - powerful jutsu that not only protects Konoha but also restores the balance of the ninja world. He uses this new - found power to face an ancient evil that has been awakened.
Well, Naruto could show Boruto his Sage Mode power. Sage Mode gives Naruto enhanced strength, speed, and the ability to sense chakra more acutely. It's a very powerful form that Naruto has mastered over time. By revealing it to Boruto, he might be teaching Boruto about the different levels of power and the hard work required to achieve such power.
In fanfictions, Naruto's power growth can be much more rapid. For instance, he might quickly master new jutsu that in the original series would have taken a long time to learn. This is because fanfiction writers often want to show Naruto at his peak or explore different power - up scenarios faster.
In the 'harry shows his power fanfic', perhaps it's a story where Harry has to show his power in a wizarding competition. He might use his unique abilities like Parseltongue to outwit his opponents and prove his worth. He could also draw on his connection with the Patronus charm to protect himself and others during the tasks.
He could be using basic chakra control techniques to suppress his power. By constantly regulating the flow of his chakra, he can keep his true power hidden. For example, he might be using a form of internal chakra suppression similar to what some ninja use to hide their presence.
Another possibility is that Naruto has his own plans and goals that he wants to achieve independently. His true power might be a key factor in these plans, and he doesn't want his parents' influence or interference. He wants to prove himself on his own terms, without relying on his family connection.
In this fanfic, Harry is the main character. However, we could also expect to see Dumbledore making an appearance. Dumbledore has always been a guiding figure for Harry, and in a story about Harry showing his power, Dumbledore might offer some wisdom or crucial information. Neville could also be a key character. He has his own growth in the original series, and in this fanfic, he could be inspired by Harry's power and contribute to the overall plot in some way.
He might show his scars to Sasuke. Given their complex relationship, it could be a powerful moment between them, a way to show Sasuke that Naruto has also faced great pain in their separation and the events that followed.
In the context of fanfiction, it might also be a plot device to explore Naruto's vulnerability. It could lead to new character developments, such as others seeing him in a new light. Maybe it causes some characters to re - evaluate their relationship with him, while for others it could be a source of inspiration, seeing that even someone as strong as Naruto has his own set of hardships.