Shinobi World No. 1.
Spring, Year 46 of Konoha.
In a secluded underground cavern.
Madara Uchiha sat in a stone chair, countless fine tubes wrapped around his withered body. The life force of the Demonic Statue of the Outer Path flowed slowly through him like blood. He had already lost his sight, but his hollow eye sockets still "looked" ahead-where Obito Uchiha sat cross-legged on a stone platform, the Mangekyō Sharingan in his left eye slowly spinning.
"Obito."
Madara's voice was hoarse, like scraping sandpaper.
"Yes."
Obito's voice was low, stripped of its former liveliness. Rin's death had been like a knife, carving out the softest part of his heart. All that remained was cold, burning-hatred.
"Starting today, I'll teach you the Uchiha's secret techniques."
Madara took an ancient scroll from inside his robes and tossed it to Obito.
"And knowledge of Yin-Yang Release."
Obito caught the scroll and unrolled it. It was densely covered in writing, along with complex runes and annotations. His gaze moved slowly across the page, his pupil contracting slightly.
"Yin-Yang Release..."
"Yes. Yin-Yang Release." Madara nodded. "Creating all things from nothing, returning all things to nothing. This is the Sage of Six Paths' power, and the source of the Uchiha."
Obito's breathing quickened slightly.
"Can... can I learn it?"
"Yes."
Madara's answer was brief and certain.
"Because you have the Sharingan. The Mangekyō Sharingan."
Obito lowered his head, looking at his scarlet eye.
"Mangekyō... Kamui..."
"Kamui is a space-time dōjutsu. A manifestation of the Sage of Six Paths' bloodline."
Madara's voice was calm.
"With it, you can move between the tangible and intangible; with it, you can evade any attack; with it, you can bring about the 'Eye of the Moon.'"
A glimmer flashed in Obito's eye.
"The Eye of the Moon..."
"Yes. The Eye