Truth-Seeking Ball

Truth-Seeking Balls are hand-sized orbs of black chakra that users can alter the shape of to serve a variety of purposes.

Acquisition
There are multiple ways to acquire the Truth-Seeking Balls:
 * Hamura and Hagoromo Ōtsutsuki both possessed Truth-Seeking Balls when they fought their mother, which they acquired through unspecified means.
 * Truth-Seeking Balls are automatically acquired upon becoming the jinchūriki of the Ten-Tails.
 * Entering Six Paths Sage Mode grants the user Truth-Seeking Balls.
 * Entering the Tenseigan Chakra Mode grants the user Truth-Seeking Balls.

Usage
The number of Truth-Seeking Balls that are acquired varies from user to user. Acquisition method may determine the number, as both Obito Uchiha and Madara Uchiha gain ten orbs upon becoming the Ten-Tails' jinchūriki; Obito initially has only two orbs, gaining the other eight once he gains control of the Ten-Tails' power. Naruto Uzumaki instead gains nine orbs, and Toneri Ōtsutsuki is depicted with an inconsistent amount. When not being used, orbs generally float behind the user's back in a circular formation; Hagoromo's float beneath him while he's levitating, and Hamura's instead float behind him in a sigmoidal formation. The orbs are always on standby once created, and users cannot create additional orbs after the initial acquisition number; thus, orbs that are lost for whatever reason cannot be replaced. Clones are not created with orbs of their own, though they are able to use the original's orbs.

Truth-Seeking Balls are composed of all five basic natures as well as Yin and Yang, in a way similar to yet surpassing kekkei genkai and kekkei tōta. If imbued with Yin–Yang Release, they can be used to neutralize ninjutsu and by extension become impervious to it; this negates the regenerative qualities of the Impure World Reincarnation, making it possible to kill or permanently damage those who have been reincarnated. Only senjutsu has been shown to consistently counter Truth-Seeking Balls, though powerful taijutsu can also damage them. If users are killed or their chakra otherwise disappears, the orbs will disintegrate in a manner similar to black receivers.

Truth-Seeking Balls are extremely destructive, capable of turning targets to dust in a similar manner to Dust Release. The orbs are similar to Tailed Beast Balls, and in fact can be used by Naruto Uzumaki to create his Tailed Beast Ball Rasenshuriken. When kept in their default sphere form, they can be used as high speed projectiles, as explosives by making them rapidly expand, or to heal the user's injuries through physical contact. Whatever their shape, users can only control them within 70 metres of their location, allowing opponents to combat them by transporting the orbs elsewhere.

Shape Transformation
Truth-Seeking Balls can be controlled individually or combined together: in both cases, the power of can be used to shape the orbs into different forms, with the shape's effects determined by how its natures are combined. Most users are able to manipulate Truth-Seeking Balls without any special effort, though Obito must pass the balls through holes that form in his hands in order to alter their form. Hiruzen Sarutobi theorizes that there is a time limit to how long the shape can be maintained, though this is never confirmed.

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.
 * By taking Madara's Six Paths Chakra, Obito is able to alter Black Zetsu's shape and use it as what is effectively a Truth-Seeking Ball.
 * In Ultimate Ninja Storm 4, Truth-Seeking Balls give off a purple glow. In his fight against Naruto and Sasuke, Obito also employs them in several ways, such as scythes, drills, spinning disks, and as hands with which to fire Tailed Beast Balls.