Truth-Seeking Ball

Upon becoming the Ten-Tails' jinchūriki, Obito Uchiha was able to use a unique form of Yin–Yang Release, which generate a malleable, black substance from his body.

Usage
This substance is highly versatile and can be used for offensive, defensive and supplementary purposes. Obito can have them pierce through the holes in his palms to become blades, wrap around him to act as a defensive shield, extend them to hit the enemy, destroying whatever it touches. It may also be used to grab opponents. This can also be formed into more sophisticated weapons such as a shakujō. According to Hiruzen Sarutobi during his analysis of this ability, the technique acts on a similar basis to Dust Release, but on a greater level in terms of shape transformation, allowing it to be constantly used for either offensive or defensive purposes. Hiruzen also notes that it is beyond both kekkei genkai and kekkei tōta, comprising at least four different nature transformations. When Obito took control of the Ten-Tails' power, Tobirama Senju states this technique could be based on the Yin–Yang Release, which allows it to nullify all ninjutsu. He continues to state that if the technique were to strike a reincarnated individual, their damages would not recover and they could die regardless of their immortality. He could also use them as a substitute for Chakra Receivers, shooting them in six directions for his Six Red Yang Formation, and create the Sword of Nunoboko.

Shape Variants
This technique can be manipulated into a variety of shapes for various purposes.

Drawbacks
According to Hiruzen, there is a limit to the duration of shape transformations that can be performed.

After seeing the effects of Gamakichi's natural energy-imbued technique on Obito, Naruto Uzumaki and Tobirama discovered that the chakra weapons were incapable of negating senjutsu. It was also shown that when the chakra weapons came in direct with natural energy-based technique, their form becomes disrupted.

Trivia

 * Surprisingly, when Hiruzen and Tobirama got hit with this technique, they recovered from it, possibly because they were hit by the initial jinchūriki form Obito used.