The Truth-seeking balls are orbs made up of black chakra, which serves variety of purposes. They can be awakened when a user becomes either the Jinchuuriki of the 10 Tails, or awakens the Six Paths Senjutsu. Truth-seeking balls are composed of all five natures and surpass even the Kekkei Tōta. They can also turn any target to dust, just by touching them, and hence is the ultimate ability.
Here are all 8 Users of the Truth Seeking Balls in Naruto that we’ve seen.
8. Asura Ōtsutsuki
Asura Ōtsutsuki was entrusted entirely with Hagoromo Ōtsutsuki’s powers. With the help of these powers, Asura awakened the Six Paths Senjutsu. By entering the Six Paths Sage Mode, he was able to manifest 9 Truth Seeking Balls behind him and also a three headed avatar, similar to that of Naruto’s Three-headed Kurama Avatar.
7. Toneri Ōtsutsuki
Toneri Ōtsutsuki was a descendent of Hamura Ōtsutsuki. By stealing Hanabi’s Byakugan, he was able to manifest a Tenaeigan in his eyes. After awakening the Tenseigan, Toneri also manifested 9 Truth-seeking balls behind him. He used them both offensively and defensively. By using the Truth-seeking balls with his chakra, Toneri created a giant golden sword, while was strong enough to split the moon in half.