The story would likely take a darker turn. His friends would be full of grief and anger. Sasuke might leave Konoha earlier in search of power to avenge Naruto. Sakura would probably struggle with her identity as a ninja without Naruto's presence to inspire her. And the village of Konoha would be in shock, with the villagers mourning the loss of someone they were starting to believe in.
One possible consequence could be a huge shift in the power dynamics among the ninja villages. Since Naruto was seen as a potential strong force, his death might make Konoha more vulnerable. Also, his friends like Sasuke and Sakura would be deeply affected. Sasuke might be driven further into his quest for power in a more reckless way out of revenge or a sense of loss. And Sakura would likely be devastated, perhaps changing her path from a healer to someone more focused on vengeance as well.
Well, if Haki was introduced in the Chunin Exams in a fanfiction, it could change things a great deal. For example, Naruto might use Haki to sense the true intentions of his opponents, like Orochimaru when he was disguised as one of the examiners. This could lead to Naruto being able to avoid some of Orochimaru's traps more easily. Also, in battles, Naruto could use Haki to predict his opponents' moves better, just like how he uses his own natural instincts in the original story. It would add a whole new layer of strategy to the battles in the Chunin Exams.
At the start, Naruto might be a bit intimidated by Pakura. But as the story progresses, he would open up to her. They could form an unlikely alliance. Naruto would share his dreams of becoming Hokage with her, and Pakura would share her experiences as a shinobi. This interaction could help Naruto grow both as a person and as a ninja during the Chunin Exams.
The Chunin Exams' storyline would be completely different. Naruto could use his time - traveling knowledge to expose the plot of some of the enemy ninjas earlier. He could also team up with some unexpected characters during the exams. For example, he might form an alliance with Kabuto, but this time with the upper hand as he knows Kabuto's true motives. This would create a whole new set of alliances and rivalries within the Chunin Exams, making for a very different and exciting story.
Well, in certain fanfiction about the Chunin Exams, Naruto could be seen as brutal because he might take advantage of his opponents' weaknesses in a rather ruthless way. He may not give them a chance to recover or adjust their strategies. Say, if an opponent is vulnerable after using a big move, Naruto might immediately strike with a powerful counter - attack instead of waiting for a fair rematch. This makes him seem brutal as it goes against the more sportsman - like nature of the regular Chunin Exams.
The story would take a very different turn. His friends would be affected. For instance, Sakura might be disappointed in him and start to question his resolve. Sasuke might see it as a sign of weakness and it could further strain their relationship. The village's perception of Naruto would also change. People who were starting to believe in him might lose faith. And his opponents in the exams would have a different outcome. Some might be disappointed they didn't get to face him fully, while others might be glad to have an easier path to victory.
The story would change drastically. First, his opponents would be in big trouble. They would have to come up with new strategies to counter such a powerful move. Second, Naruto's reputation among the ninja community would skyrocket. People would start to see him as a real force to be reckoned with. Third, it could also lead to some political implications. Other villages might view Konoha as more of a threat because of Naruto's power.
Devil Fruits would make the Chunin Exams far more unpredictable. Some characters could suddenly have powers like flight or super strength. This would disrupt the normal balance of power among the genin. For instance, a character with a Zoan - type Devil Fruit could transform into a powerful beast, giving them an advantage in combat.
Well, one thing that could happen is that Naruto, with his knowledge of future events, could easily ace the written part of the Chunin Exams. He might also be able to prevent some of the chaos that Orochimaru caused during the exams. For example, he could warn the proctors about Orochimaru's infiltration in advance.
Grimmjow could be seen as a new kind of threat. The Chunin Exams are a test of a ninja's skills, and Grimmjow has skills that are completely different from the ninja arts. His spiritual power could be something that the ninja have never encountered before. So, he could either be a great ally if someone can convince him to work with them, or a terrifying enemy. He could also disrupt the normal flow of the exams as he doesn't care about the rules and regulations set for the ninja.