The air in the valley seemed to freeze solid. Sasuke Uchiha's sudden arrival, and the black flames of Amaterasu that had precisely stopped Obito, brought an unexpected turn to a battle that had seemed hopeless.
"Sasuke?!" Naruto stared at that familiar yet unfamiliar figure, overwhelmed with surprise and joy. But as he sensed Sasuke's increasingly dark chakra, entangled with dark energy, an indescribable worry crept into his happiness.
Ling lay collapsed on the ground. Through Water Mirror Insight into Principle and its keen perception of the essence of energy, he finally "saw" clearly the patterns in Obito's eye-utterly unlike the Sharingan, and imbued with the power of all creation.
Those eyes... Ling was deeply shaken. The Rinnegan?! How is that possible... The Rinnegan is the eye of the Sage. It requires the fusion of Indra's and Asura's chakra to awaken in Indra's reincarnation... How could he...
Obito slowly turned around. Kamui's intangibility allowed the flames of Amaterasu to pass through his arm without inflicting any real damage, but for the first time, a hint of scrutiny entered his gaze as he looked at Sasuke. He did not immediately resume his attack on Naruto. Sasuke's arrival seemed to warrant more attention than taking the Nine-Tails.
"Just as I thought..." Sasuke braced one hand against the rock wall, panting lightly. He bore the wounds and exhaustion of his bitter battle in Annihilation Valley, but his Mangekyō Sharingan burned with a fire colder than Amaterasu as he stared fixedly at the Rinnegan in Obito's left eye. "You stole Nagato's power... No, the 'Sacred Lord' helped you 'modify' that eye, didn't he?"
His voice was hoarse, yet it cut through the silence like a blade, exposing a shocking truth.
"In Annihilation Valley, I sensed more than dark power distorting the Nether Purification Stone. Deep