The character needs to respect the ninja code. Even though they come from a different world or life, the ninja code is the foundation of the Boruto world. They should abide by it while also bringing in their own modern values in a way that doesn't conflict too much. For instance, they can introduce new ways of training while still following the principles of honor and loyalty in the ninja world.
The reincarnated character might first struggle with the concept of such extreme power like Saitama's. They could initially be in awe and a bit scared. But as time goes on, they start to learn from Saitama. They might adapt by training with him, observing his nonchalant attitude towards fighting, and trying to incorporate that into their own approach. They also have to adapt to the different types of villains and heroes in the world. For example, dealing with heroes who have more complex personalities compared to what they're used to.
Well, to adapt in a Naruto fanfiction world where you're reborn as a reader, start with understanding the power hierarchy. Know who the strong clans are, like the Uchiha and Hyuga. Next, get used to the shinobi way of life. This includes taking on missions, respecting your village, and protecting your comrades. You might also want to keep an eye on the political situation. There are often tensions between villages, and being aware of this can help you stay out of trouble.
The other ninja villages would also be affected. Naruto was a key figure in maintaining peace and balance among the villages. His death could lead to old rivalries resurfacing. Without Boruto, the future that everyone had envisioned for a more united ninja world would be in jeopardy. Some villages might even see this as an opportunity to expand their territories or influence.
The villagers would likely be in shock. Naruto is a beloved figure, but killing his own son would be a very controversial act. Some might turn against Naruto, believing he has gone too far. Others might understand his reasons if they knew the full story, but still struggle with the morality of it.
Well, they'd first have to deal with Salem's powers. It's not easy to suddenly have such great and dark powers. They might struggle to control them at first. For example, Salem can manipulate Grimm, and the reincarnated 'Si' might accidentally summon Grimm when they don't mean to, causing chaos in the areas around them.
The ninja world would likely be filled with a mix of reactions. Some would see it as a positive sign of unity between different clans. Others might be worried about the power the baby could potentially have. There could be those who would try to use the baby for their own political or power - hungry motives.
Sasuke's sharingan would give him a huge advantage in the Yakuza world. He could use it to read the intentions of his enemies, predict their moves during fights or negotiations. Sakura's super strength and medical skills also come in handy. Her strength can be used in combat situations against Yakuza thugs, and her medical skills can be used to treat any injuries they might get during their Yakuza - related adventures.
The main character often uses their prior knowledge. If they were a scientist in their past life, they might use scientific principles to understand magic in the new world. They also learn from the locals. By observing how people live, trade, and interact, they pick up the social norms. And they start to train their new - found powers, getting used to how magic or special abilities work in this world.
Well, characters often adapt in different ways. One way is through trial and error. They might try to fight small monsters at first and learn from their mistakes. They could also adapt by observing the other heroes. For instance, seeing how King acts so confident even though he's not that strong gives them an idea of how to survive in this world. And they might adapt to the new world by finding a unique role for themselves. If they have a special skill like cooking, they could open a restaurant for the heroes and monsters alike.
Percy would need to learn how to be stealthy. He's used to fighting out in the open as a demigod, but as a ninja, he'd have to blend into the shadows. He could use his powers over water to create distractions or cover his movements, like making a mist to hide in.