One of the most remarkable facets of the Naruto universe is its ability to nuance morality. While its villains may not always be the most sympathetic, they oftentimes at least have understandable motivations behind the actions they take.
Similarly, many of the heroes possess jutsu so insidious that one might expect to see it from the series' antagonists. By acknowledging the most wicked abilities that Konoha and its allies use against their opposition, we can fully appreciate how morally gray the shinobi world actually is, especially when such techniques go unchastised by Naruto himself.
10 Ibiki Has The Ability To Place His Enemies In a Torture Chamber And Tie Them Up In Razor Wires
Tasked with extracting intel from Konoha's many enemies, Ibiki's means of doing so are less than glamorous. Using genjutsu, he can place his enemies in a torture chamber, agonizingly tightening the razor wires around their body until they surrender and tell him everything he wants to know.
Unfortunately, when the Six Paths of Pain visited the Leaf, he did not realize that they ironically could not feel pain themselves. This made his capture of one of Nagato's minions unsuccessful, as he could not make use of the psychological agony he had hoped to inflict on his victim.
9 Anko Has The Ability To Turn Their Limbs Into Snakes
The former pupil of Orochimaru, it is no surprise that Anko has retained some of his teachings. She is able to turn parts of her body into snakes, as she did in her battle against Kabuto.
While this is a clearly villainous technique, her skills were nonetheless instrumental in tracking down her ex master and his hordes of amoral minions. Unfortunately, she was not able to muster her jutsu to the caliber Kabuto was, resulting with her capture and imprisonment during the Forth War arc. However, given the augmentations he had received, this may speak more to his strength than her weakness.
8 Ino Can Turn Her Opponents Into Puppets
Ino's "Mind Transfer" allows her to dominate the will of her opponents, worming her way into their consciousness and puppeteering their body. Needless to say, such a technique is morally questionable at best, especially when can use it to force her quarry into betraying their comrades.
The subject of the transfer's consciousness has nowhere to retreat as this ability is utilized, being made to watch as the shinobi manipulates their figure. It takes an unusually strong will to break the spell after it has been cast, as seen in the instance of Sakura Haruno during the Chunin Exam.
7 Gaara Can Crush The Cells of His Enemies
While Gaara's heart may have been turned toward good after his fateful battle against Naruto Uzumaki, he has not only retained the horrifying jutsu at his disposal, he has made his attacks even more disturbing (destroying his opponents' bodies from the inside by crushing their cells with grains of sand).
His most iconic ability is the "Sand Coffin," where he entombs his opponent and smashes the life from the body. It was one of the goriest jutsu to be featured in the entirety of the original series and traumatized many of the shinobi who survived.
6 Shino Can Unleash Swarms Of Bugs
One of the most skilled members of the Aburame clan, Shino's own body was a nest for bugs. Their relationship was symbiotic; so long as their host accommodated them, they would strike out at his enemies, ripping through their flesh and muscle with tiny teeth and siphoning the chakra from their carcasses.
Often, they'll attack in insurmountably massive hordes that many shinobi have no means of countering. This makes the insect wielder a terrifying adversary to battle, especially with his concealed face and reclusive mannerisms. Should he have been given more opportunities for combat in the series, the potential of his jutsu would have been clearer.
5 Itachi Can Unleash Unimaginable Pain On His Opponents
While Itachi may have appeared as a villain first in the series, it was later revealed that his intentions had been for the Leaf's benefit the entire time, as proven through his contributions in Sasuke's fight against Kabuto.
All the same, his genjutsu might cast doubt upon his morality. He was able to inflict such unimaginable pain on his adversaries that it psychologically traumatized Kakashi Hatake, an Anbu ninja and one of the most staunch protagonists in the series. The elder Uchiha accomplished this through the sinister potential of his sharingan.
4 Yamato Can Manipulate Wood
Without understanding Yamato's origins, his wood style jutsu may not seem evil. Using it, he was able to aid in the reconstruction after Pain's devastation and could even reel in Naruto when Kurama got out of control.
However, his power belies a darker secret. The captain was an experiment of Orochimaru, who was determined to properly harness Hashirama cells. That is why his talents are unique specifically to him and are seen so rarely throughout the rest of the cast ~ including the villains as much as the heroes.
3 Kankuro Can Also Turn His Enemies Into Puppets
As a hero, Kankuro's means of defeating his opponents are perhaps more morbid and grotesque than even that of his brother, Gaara. With his many puppets, he can poison, decapitate, and mangle those who contend the Sand village's objectives.
The extent of his "Puppet Show" was demonstrated during his fight against Sakkon of the Sound Four. He sealed the shinobi and his brother within one of his creations, bringing down jagged weapons from all directions. What was left of the ninja thereafter was the blood gently seeping through the grooves of the doll, heralding Kankuro's success.
2 Shikamaru Can Possess Those Who Cross His Shadow
A brilliant tactician, Shikamaru's "Shadow Possession" jutsu could paralyze any target caught within his shadow. Though this may not seem evil at first, he has used this skill to draw an opponent's weapon and force them to stab themselves with their own kunai.
Since his introduction, he has also refined this talent to include shadow strangulation. As the name suggests, a dark hand crawls up their body once they have been paralyzed, choking the life from them. Since they are powerless to resist, they could only watch their own demise.
1 Hiruzen Sarutobi Can Use The Reaper Death Seal
While the Third Hokage prefers to avoid this technique, he was willing to use the Reaper Death Seal under dire circumstances. This was both because it was forbidden and for what it entailed to himself and his enemies.
Whatever the shinigami was able to clutch would have their souls destroyed along with his own. Through this technique, he was able not only to cripple Orochimaru but also to defeat the combined attacks of the resurrected first and second Hokages. With the price associated behind the Reaper Death Seal, it was the last jutsu Sarutobi cast before his resurrection.