The Chunin Exams Arc in Naruto brought a certain pace to the anime, which couldn't be found during Kakashi's adventure with Naruto, Sasuke, and Sakura into the mist. This was just the kind of kick Team 7 needed after their fight against Zabuza.
Chunin is a post higher than Genin and very few Shinobi gain the rank. The Chunin Exams aren't everyone's cup of tea. There are 3 steps to go through in the exams and the tasks keep on getting harder as the participants move on. Nevertheless, during the Chunin Exams Arc, the young Shinobi weren't the only attraction as something more sinister was being planned by Orochimaru.
10 Kabuto's Manipulation of Sakura, Sasuke, & Naruto for Orochimaru
Kabuto looked like a simple Shinobi who was trying to help the rookie Genins when he first showed up but all the while, he was playing a different card. He was manipulating Sakura, Sasuke, and Naruto for Orochimaru.
While Sasuke found something off about Kabuto from the start, Naruto and Sakura were sold. It could be seen from the sheer shock on Naruto's face when Kabuto battled Tsunade, Shizune, and Jiraiya after the end of the Chunin Exams.
9 wanting to test the Uchiha Clan's strength, Orochimaru left his curse mark on Sasuke
Orochimaru showed up in a very weird human form, looking for Sasuke Uchiha. He threatened to kill the entirety of Team 7 but he never really had that intention on his mind. He simply wanted to test the Uchiha's Clan strength.
Naruto tried his best to protect Sasuke, who got cold feet before the former became unconscious. In the end, Orochimaru left his curse mark on Sasuke, which wasn't a good thing, at all.
8 Gaara used Sand Jutsu on his Murderous Rampage
Gaara looked like a respectful guy when he stopped Kankuro from inflicting pain on a young child. But as it turned out, Gaara was evil incarnate. Akamaru's smell relayed the same thing to Kiba, who went to see what Gaara was all about with Hinata and Shino.
The Shinobi from Sand Village used his Sand Jutsu to kill three other participants in the Chunin Exam, without flinching an eye. Kiba was trembling with fear after seeing that.
7 Sasuke Breaking Bad, as the Curse Mark started spreading on his whole body
The first instance of the influence of the Orochimaru Curse Mark could be seen when the Sound Village Ninjas started dominating Sakura, Shikamaru, Ino, Rock Lee, etc. Sasuke woke up after a while and the Curse Mark started spreading on his whole body.
The anger he had inside started growing and he came very close to killing the Sand Village Ninjas until Sakura begged him to stop. It was a very emotional moment where Sasuke's evil inheritance was visible.
6 The Sand Spirit could have wiped the Leaf Village in an instant
The day he was born, the Sand Spirit was sealed inside him, which made his murderous intent come to the fore. He first transformed against Sasuke and left the latter for dead before Naruto stepped up to give the Sand Village Ninja a fight.
It led to a full transformation as he became a literal monster who could wipe the Leaf Village in an instant. Thankfully, Naruto had the Summoning Jutsu on lock and he fought tooth and nail to protect his friends.
5 Hinata & Neji's Confrontation — they put up an absolute clinic of a match
The Hyuga Clan had a very good showing in the Chunin Exams, thanks to Neji and Hinata, who put up an absolute clinic of a match. But the tempers were soaring high as the family dislike between the two showed up.
Neji continually insulted a weaker Hinata and it looked like Neji wouldn't think twice before killing his cousin sister. Hinata tried everything she had but came up short and the ugliness of the Hyuga Clan came to the fore.
4 Sakura Bruised & Battered
Sakura was the side character for the entirety of the Zabuza Arc and even though she is a decent Shinobi herself, she never got the ability to showcase her abilities. That was until she had to protect Sasuke and Naruto with her life.
She sacrificed her long hair and fought with the Sound Ninjas with all her might. Towards the end, she was caught in the huge hand of the Sand Spirit where she was suffocating. If Naruto hadn't brought down the monster, she could've easily died.
3 Leaf Village Invasion — the Leaf Village was shocked by the sheer number of attackers
The plan of the Sand Village, as well as the Sound Village, was to invade the Leaf Village when Sasuke battled with Gaara. What everyone didn't know was Orochimaru had killed Lord Kazekage of the Sand Village, took his place, and manipulated all of them.
Kakashi, Guy, and all the elite Shinobis had to fight the invading Ninjas, while the village was being evacuated. Despite having tough security measures, the Leaf Village was shocked by the sheer number of attackers.
2 Rock Lee's Fate — Gaara broke one of Lee's hands & legs, which the doctors revealed was almost impossible to recover from
Rock Lee faced Gaara with little to no expectation of coming out on top. With no Ninjutsu and Genjutsu to rely on, it felt like a matter of time before Gaara would figure Lee out. But the Taijutsu specialist had some trump cards up his sleeve.
He opened up the gates of the Chakra inside his body and absolutely pelted Gaara. The Sand Village Ninja could barely stand and now, he wanted to kill Lee. He broke one of Lee's hands and legs, which the doctors revealed was almost impossible to recover from.
1 Third Hokage's Death
The Third Hokage, aka Sarutobi Sensei, had to fight his student Orochimaru in order to protect his village. Even though he was quite old, he gave Orochimaru a run for his money.
The evil rogue Ninja even brought out the clones of the First and the Second Hokage but it wasn't enough. In the end, Sarutobi had to use the Grim Reaper Death Seal Jutsu to end Orochimaru's rampage. The Third Hokage died an absolute hero.