Truth-Seeking Ball

Truth-Seeking Balls are spheres of malleable black chakra composed of all five nature transformations and Yin–Yang Release, capable of negating all forms of ninjutsu. Each is about the size of a fist and hides within the power to completely obliterate a forest.

Usage
Once formed, these balls generally float in a circular formation behind the user's back, and each can be individually manipulated. They are a type of technique that is always on standby, rather than activating from nothing. The balls can be shaped into a variety of forms, and the many natures comprising them can be combined to produce various effects. Obito shaped the balls by having them pierce through holes that temporarily formed in his hands, whereas other users forego this process. They are able to serve a variety of functions, such as forming shields, launching as high-speed projectiles, and rapidly expanding to produce massive explosions. As the chakra comprising them is highly durable, the balls can serve as an effective defence, only taking damage from extremely powerful techniques. The black chakra can also seemingly be converted into chakra receivers to activate other techniques, as well as used to create the legendary Sword of Nunoboko.

The Truth-Seeking Balls are capable of using attacks that instantly turn their target to dust, prompting Hiruzen Sarutobi to compare them to Dust Release, though he noted that their fluid nature allows them to serve both offensive and defensive purposes, and they can be maintained. The balls can utilise Yin–Yang Release to nullify any ninjutsu they come in contact with; as a result, any damage done to a reincarnated individual — who can usually regenerate infinitely — cannot be repaired, and said individual can die. However, this nullification effect does not appear to be automatic, as Obito's Truth-Seeking Balls did not display it prior to him gaining control over the Ten-Tails' power. The balls can also quickly heal the user through contact, glowing red while doing so in the anime. Naruto's Truth-Seeking Balls are able to utilise his to effectively damage shadows in the invisible world of Limbo. 

Shape Variants
Although the Truth-Seeking Balls are usually orbs, their form can be freely changed into what the user desires. They can grab enemies far away in the form of hands, or be thrown in the form of weapons. Because the high-density chakra is in a condensed state, it can be pulled and stretched into a smooth and flat consistency, as well as freely manipulated into any other shape.

Drawbacks
The user starts with a set amount of balls and can only control them within 70 metres of their location, allowing opponents to separate them from the user by transporting them elsewhere. If they are somehow destroyed or otherwise not retrieved by the user, they appear to be permanently lost, as no user has demonstrated the ability to replace them. Similarly, any clones produced by the user will not have their own Truth-Seeking Balls, though it is possible for the user to pass them over to a clone. Hiruzen suspected that there is a time limit for how long the balls can undergo each shape transformation. When the Truth-Seeking Balls expand, they are capable of damaging the user's own body provided they are not protected by other balls. Additionally, the balls are incapable of negating senjutsu, and their form becomes disrupted upon coming into contact with senjutsu chakra. In the event that the user is killed or their chakra otherwise disappears, the balls will disintegrate in the same manner as the chakra receivers.

Trivia

 * The term comes from Mahāyāna Buddhism. The Kanji 求 means to wish for, while the  in Mahāyāna doctrine is to find the ultimate truth within one's own mind.
 * Suspecting this technique to be a combination of at least four nature transformations, Hiruzen concluded that it is beyond both kekkei genkai and kekkei tōta. The fourth databook confirms this, but only classifies this technique as ninjutsu.
 * When a jinchūriki of the Ten-Tails gains control over the beast, the shakujō variant seems to instinctively form in their hand. Obito and Madara Uchiha each wielded one half of Hagoromo Ōtsutsuki's complete shakujō.
 * Obito Uchiha was able to create a makeshift Truth-Seeking Ball out of Black Zetsu's black mass and shape it into a shakujō. Additionally, he absorbed some of Madara's senjutsu chakra and applied it to the staff, making it invulnerable to Madara's own Truth-Seeking Balls.
 * The fourth databook states that the Truth-Seeking Balls appear when one awakens the Six Paths Senjutsu, but does not categorise this technique as senjutsu. Kaguya, Hamura and Toneri have all made use of this technique without known usage of senjutsu.
 * In Naruto Shippūden: Ultimate Ninja Storm 4, the Truth-Seeking Balls give off a purple glow.