The heroes of the Naruto universe have generally been portrayed in a positive and morally righteous light. Although there are a few unique outliers, most heroes never resort to extreme measures in order to see their goals through.
However, there have been some instances where a character has gone too far in pursuing their goals. Whether from a place of emotional vulnerability or simply seeking a more expedient solution to their problem, their actions can make a reasonable individual question whether or not they can be considered "good" to begin with.
10 Shikamaru Devised A Brutal Ending For Hidan
After Asuma's death, Shikamaru was consumed by rage, much like Sasuke. Obsessed with the prospect of getting revenge, he meticulously planned the Akatsuki member's downfall for the next time they met.
It wasn't long before he had his chance. By using the shadow possession to lure Hidan into a paper bomb trap, he managed to destroy the villain's. However, instead of putting him out of his misery, he buried him alive, thereby prolonging his opponent's suffering for the sole purpose of slaking his anger.
9 Kankuro Butchered Sakon/Ukon In A Grotesque Trap
During the Sasuke retrieval mission, Kiba was in desperate need of help. After coming to his aid, Kankuro faced off against the sinister brothers known as Sakon/Ukon.
He managed to capture them within his "Crow" puppet, meaning that he could've taken them back to the Leaf for questioning. However, Kankuro wasn't interested in mercy; instead, he used his spare puppet to impale the villains through the grooves in his doll's body. Their deaths were excruciating, and their final screams of pain chilled Kiba to the bone. The Sand Village's ninja were as strong as they were terrifying.
8 The Fourth Raikage Was Willing To Risk An Arm & A Leg To Kill Sasuke
The battle between the Fourth Raikage and Sasuke Uchiha was as brief as it was brutal. Having been convinced that the wayward ninja was responsible for the disappearance of his brother, the Cloud's leader willingly punched through an Amaterasu in order to hurt him.
After getting Sasuke on the ropes, he was fully prepared to finish him off by sacrificing his leg. However, Gaara intervened on both of their behalves, allowing an opportunity for Sasuke to slip away and pursue his real target - Danzo Shimura.
7 Itachi Committed Genocide On His Clan, Murdered His Parents, & Emotionally Tormented His Brother
Although it was later revealed that the Uchiha massacre prevented a world war, Itachi went about it in the most unconscionably brutal way possible. After dishonorably slaughtering his kin in their sleep, he made sure Sasuke was present for the death of their own parents.
The idea behind killing them while his young brother watched was to evolve his sharingan and encourage him to become a fine protector of the Leaf. However, it backfired and instead made him a power-crazed, vengeance-obsessed maniac.
6 Neji Beat Hinata To A Pulp Even Though He Knew How Much Weaker She Was Than Him
When the fight between Neji and Hinata was announced, the outcome was practically predetermined. Both ninja had sparred under the orders of Hiashi, with Neji decisively winning every round.
Despite how he knew Hinata had her pride as a shinobi to risk, he only gave her a single opportunity to back down. When the match finally began, he beat her savagely until she could barely speak. Naruto was disgusted by his brutality and brought his anger down on him in the semifinals.
5 Sasuke Almost Ripped Off Zaku's Arms After He Was Already Beaten
After waking up from a terrifying encounter with Orochimaru, Sasuke noticed Zaku harassing Sakura. They had recently beaten up Rock Lee, and without immediate action, the kunoichi would be next.
Empowered by the curse mark, Sasuke overwhelmed his adversaries effortlessly. However, victory alone wasn't enough. He pressed his foot against Zaku's back and intended to rip off the villain's arms before Sakura stopped him. Should Sasuke have actually been successful, the Chunin Exams would've taken an extremely dark turn.
4 Hiruzen Enabled Danzo's Crimes, Including His Own Assassination Attempt
Hiruzen Sarutobi was lenient with Danzo to a fault. In addition to sparing him after discovering his role in Shisui's death, he even overlooked the man's attempt to assassinate him in the forest, only requesting that "it not happen again."
Although the Foundation was allegedly disbanded, Danzo was still able to act with authority in the Leaf. This was how he coerced the Aburame clan into enlisting Torune, a young ninja who would later become Danzo's secret weapon and personal bodyguard.
3 Sakura Was Willing To Defect From Konoha For Sasuke's Sake
When Sasuke announced his intentions to leave Konoha forever, Sakura was completely crushed. Since attempting to reason with him failed, she offered to join his cause instead.
This was extremely problematic, as it entails that Sakura's allegiance could be bought in exchange for Sasuke's affection. Moreover, it illustrated how little of an individual identity she had up until that point since impressing her beloved was virtually her only motive for improving. She would even overlook multiple attempts on her life in order to be with him after his final battle against Naruto at the Valley Of The End.
2 Naruto Lost Control Of Himself Against Orochimaru & Nearly Got Sakura Hurt
Having finally encountered Orochimaru after years spent in training, Naruto was ready for answers. He anticipated that the Sannin knew Sasuke's location and was prepared to rip the answers from his flesh.
Unfortunately, Naruto got far too caught up in the moment for his own good. By borrowing Kurama's chakra in order to even their differential of strength, he lost control of his free will. Should Yamato not have been there to seal the Nine-Tails, he could have hurt or even killed his own comrades.
1 Kakashi Performed The Atrocious "Thousand Years Of Death" Against His Own Students
Perhaps Kakashi's most notorious action was during the bell trial against Team Seven. Having easily capitalized on Naruto's sloppy and aggressive fighting style, he performed the "Thousand Years Of Death" technique. He put his fingers in a place Naruto wouldn't soon forget and sent him flying into the trees.
Although his actions were played for comedic effect, they're extremely abusive and appalling when analyzed objectively. In a realistic environment, Kakashi would've lost his ability to teach as a consequence of his actions at the very least.