In this kind of fanfiction, Naruto might have used his new and powerful jutsu that he developed secretly. Maybe it was a super - enhanced Rasengan with some special chakra nature added to it, which was strong enough to overpower Orochimaru.
Since Orochimaru had many experiments and secrets, his death at Naruto's hands in the Chunin Exams fanfiction could lead to a scramble for his research. Other villages or even some rogue ninjas might try to steal his notes and facilities. In Konoha, Naruto might be pressured to reveal what he knew about Orochimaru's plans and secrets. This could put him in a difficult position as he may not know everything. Also, Sasuke, who had a connection with Orochimaru, might have a complex reaction. He could be angry at Naruto for killing Orochimaru, or he could see it as a sign of Naruto's strength and be motivated to become stronger himself.
In such a fanfiction, the plot could involve Naruto being pushed to the extreme during the Chunin Exams. Maybe he witnesses some great injustice or threat to his friends that makes him cross his moral line and kill. For example, if an enemy tries to assassinate Sasuke during the exams and Naruto, in a fit of rage and desperation to protect his friend, uses a powerful jutsu that ends up killing the attacker.
He might kill an enemy shinobi from another village. For instance, if there is a particularly aggressive and cruel shinobi from the Sand Village during the Chunin Exams who poses a great threat to Naruto's friends or the Leaf Village in general, Naruto could be forced to kill him in self - defense or to protect others.
One interesting aspect in Naruto fanfiction about Fuinjutsu in the Chunin Exams could be a character using unique Fuinjutsu techniques that were not shown in the original series during the exams. For example, a genin might create a sealing jutsu to temporarily disable an opponent's chakra flow in a creative way that surprises everyone.
In a Chunin Exams fanfiction, Naruto and Temari could be paired in a team - up for a special mission within the exams. Their personalities would clash at first. Naruto is all about enthusiasm and impulsiveness, while Temari is more level - headed. However, they gradually learn to work together. Maybe they face a powerful enemy that requires both Naruto's brute strength and Temari's strategic thinking to defeat.
One possible fanfiction could be where Naruto has godlike powers during the Chunin Exams. He might effortlessly defeat all his opponents with super - strong jutsus. For example, his Rasengan could be a hundred times more powerful than in the original story, and he could use it to break through any defense. This would completely change the dynamic of the Chunin Exams as he would be a near - unbeatable force.
You could also write a fanfic where a Bleach character accidentally uses a powerful ability during the Chunin Exams that causes a rift between the two worlds. The Naruto characters think it's an attack, and the Bleach character has to prove that it was a mistake. This leads to a lot of misunderstandings and eventually a greater understanding between the two groups as they try to fix the rift.
One interesting idea could be that characters from Bleach are somehow transported to the Naruto world during the Chunin Exams. For example, Ichigo could end up participating in the exams. He might use his Soul Reaper powers in the forest of death, which would give him an edge against the ninja there. His Zanpakuto skills could be misinterpreted as some kind of advanced ninja tool or jutsu.
In Naruto fanfiction where Devil Fruits are involved in the Chunin Exams, it could lead to some really interesting scenarios. For example, a character might eat a Devil Fruit and gain unique powers that completely change the dynamics of the exams. They could use abilities like Luffy's stretchiness from the Gomu Gomu no Mi to reach far - off targets or avoid attacks in a creative way.