The moral is about priorities. Just like in the story, if you put the big rocks (important things) in first, the small rocks (less important things) can still fit around them. It tells us to focus on the important tasks or aspects in life first, and then the minor ones can be dealt with.
Maybe an ancient sage in Naruto's own world who has long - been in seclusion. This sage has knowledge of different power systems beyond just chakra. He notices Naruto's pure heart and strong will and decides to pass on his knowledge of haki to Naruto, believing that Naruto can use it for the greater good of the ninja world.
In 'naruto haki fanfic', Haki can change the Naruto universe by adding a new layer of power. For example, it can make battles more complex as characters now have to consider both chakra and Haki. It might also change the way characters interact with each other, as those with Haki could sense things differently.
Percy often uses Observation Haki to anticipate the attacks of his enemies. He can sense their movements and intentions, which gives him an edge in combat, especially against fast - moving or sneaky foes like some of the monsters in the Percy Jackson world.
The 'big rocks little rocks story' is about how we should arrange our priorities. Let's say you have a day, or a week, or a life. The big rocks could be things like getting an education, taking care of your parents when they're old. These are big, important things that require a significant amount of time and attention. The little rocks might be things like watching TV or chatting aimlessly with friends for a short while. If you focus on the little rocks all the time, you'll never find time for the big rocks. So, it's crucial to recognize the big rocks and give them the priority they deserve in our lives.
Haki can completely shift the power dynamics. If a character like Ron suddenly discovers Haki, he could become a much more formidable opponent. He might be able to use it to intimidate Death Eaters or other dark wizards, adding an edge to his character that wasn't there before.
In some fanfictions, Naruto might discover haki during a particularly intense battle. Maybe when facing an enemy with an unusual power that his regular jutsu can't handle, he unknowingly taps into his latent haki ability.
An OC's Haki can be developed through intense training. Just like how Luffy and the others train in the One Piece world. They could face difficult opponents and learn from each battle, gradually strengthening their Haki. For example, if they constantly fight against Logia - type devil fruit users, their Armament Haki would improve to counter their intangible forms.
You can apply it by first identifying your big rocks. For example, if your big rock is exercise for better health, make sure you schedule it in your day first. Then the little rocks like checking social media can be done around it.
I think Conqueror's Haki would suit Naruto. He has that natural leadership and strong will, just like characters in One Piece who possess Conqueror's Haki. It would be a great addition to his existing confident and determined personality.