One new ability could be enhanced perception. Characters with Haki could sense the presence of hidden enemies during the Chunin Exams. For example, Sasuke could use Haki to detect any assassins sent by Orochimaru that are lurking in the shadows. Another ability would be the power to intimidate opponents. Just like how Luffy uses his Conqueror's Haki in One Piece, in the Naruto fanfiction, a character like Gaara could use Haki to make his opponents tremble in fear, giving him an edge in battles without even having to make a move.
In a Naruto Chunin Exams fanfiction, characters could gain the ability to harden their bodies using Haki. This would be useful in close - combat situations. Rock Lee, for instance, could use Haki to make his punches even more powerful and his body more resistant to damage. Also, characters could use Haki to disrupt the chakra flow of their opponents. This would be a new and unique way to defeat enemies. For example, Shikamaru could use Haki to interfere with an opponent's chakra while using his shadow - possession jutsu, making it more effective.
Characters in the Naruto Chunin Exams fanfiction with Haki could gain the ability to foresee attacks. This is similar to the precognition that some characters with Sharingan have, but it would be a different mechanism. Hinata could use Haki to anticipate the attacks of her opponents, especially in her fight against stronger opponents like Temari. Additionally, the use of Haki could give characters the ability to resist genjutsu. Since Haki is related to the willpower, a strong - willed character like Naruto could use his Haki to break free from genjutsu more easily, which would be a significant advantage in the Chunin Exams.
One of the new abilities Naruto could gain is better information - gathering skills. Since ANBU are often involved in intelligence work, Naruto could use this in the Chunin Exams to find out his opponents' weaknesses. Also, he could learn how to use chakra in more creative ways, like creating more complex and powerful ninjutsu. This would set him apart from other candidates in the exams as he would have abilities that are not commonly seen among genin.
One possibility is that he gains enhanced speed and stealth. As a chunin, he'd need to be more covert in his missions. He could learn to move so quietly that even sensors would have a hard time detecting him. And his speed could be on a level where he can quickly close the gap between him and his enemies without them realizing it until it's too late.
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.
There could be a new character who is a descendant of an ancient clan that once had the Rinnegan. This character might show up during the Chunin Exams to either help or hinder the current Rinnegan user. They might have some knowledge about the Rinnegan that others don't. Also, an anti - Rinnegan organization's agent could be introduced. They would be there to try and eliminate the Rinnegan user during the exams, thinking they are a threat to the balance of power.
She could teach him a genjutsu - based jutsu. For instance, a genjutsu that makes the opponent see multiple copies of Naruto, confusing them about which one is real. This would be useful in the Chunin Exams as it can give Naruto an edge in combat.
He could probably gain the ability to phase through objects. Just like wraiths are often depicted as being able to pass through solid things. This would give him an edge in combat and also in sneaking around.
One skill Naruto could pick up is better chakra control for physical attacks. Gai may show Naruto how to focus his chakra more precisely in his limbs when doing taijutsu. This would make his attacks more powerful. Also, Naruto might learn some stealth techniques from Gai. Gai could teach Naruto how to move quietly and quickly, which is very useful in the Chunin Exams where surprise attacks can be a big advantage.
The sword could give Naruto an advantage in close - quarter combat. Since Naruto is mainly known for his long - range attacks and his ability to transform into the Nine - Tails, having Zabuza's sword would force him to improve his close - combat skills. This could lead to him developing new evasion and counter - attack maneuvers, making him a more well - rounded fighter in the fanfiction.
A new character could be a young Uchiha who has just awakened their Sharingan but is very shy and inexperienced. They enter the Chunin Exams and are constantly underestimated because of their quiet nature. But as the exams progress, they start to show amazing potential with their Sharingan, for example, being able to quickly analyze and copy complex jutsu. Another interesting character could be a non - Uchiha who has studied the Sharingan extensively and has developed techniques to counter it. This character would add an interesting dynamic to the Chunin Exams as they would be a threat to the Uchiha participants.
One possible plot could be that Naruto and Yugito are both entered into the Chunin Exams by their respective villages as top - notch genin. During the written test, Naruto struggles a bit with the traditional knowledge but uses his quick thinking and observational skills to pass. Yugito, on the other hand, aces it with her calm and collected nature. As the practical exams start, they are pitted against different opponents at first. But then, due to some unforeseen circumstances like an attack on the exam venue by a rogue ninja group, they have to team up to defend the other examinees and the integrity of the exams.