[POV: 3rd Person]
[Scene: Hokage Office]
[Track Change: Naruto Shippuden Blood Prison 'Ceremony']
"Which brings us to the generation before the present. The last reincarnations were people you all know very well, Hashirama Senju as Ashura and Madara Uchiha as Indra." Renjiro finished.
"WHAT!?" everyone yelled.
"Indeed, Hashirama and Madara were both reincarnations of the sons of the Sage of the Six Paths. The age-old conflict of the Senju and Uchiha? That was Black Zetsu's stage, after the battle at the Valley of the End, where it was said Madara died, Zetsu's plan should have ended till the next reincarnation, which only starts when both people are dead.
However, unexpectedly Madara survived, using a Uchiha clan specific forbidden technique, [Izanagi]. This technique sacrifices a Sharingan eye, normal sight included, to cast a Genjutsu that essentially rewrites reality, undoing damage or even death that occurs during the techniques duration. Hashirama was known for his strong body and regeneration, and before Madara faked his death, he bit off some of Hashirama's flesh, later grafting it onto his own body.
Over the course of many years, due ONLY to being Indra's reincarnation, he was miraculously able to endure Hashirama's flesh and Ashura's Chakra from killing him, and like stated on the Uchiha stone tablet, when two opposites combine they are able to awaken a greater power, the Rinnegan. This is when Black Zetsu's plan could finally take off.
However, Madara was now too old to carry out Black Zetsu's manipulation, and he needed to find a successor. Madara noticed that the Uchiha clan is a clan of highly emotional people. When a large enough stimulus is given an Uchiha will awaken their Sharingan depending on how large said stimulus is. While some Uchiha have awakened their Sharingan through sheer joy or happiness, most awaken theirs through loss.
The deeper that loss is felt the stronger the Sharingan awakened is, where some Uchiha only awaken one-tomoe, some awaken the two-tomoe at the start. Madara found a single Uchiha to make his successor, he was a very joyful boy with lots of love for everyone in the village, he would go out of his way to help anyone, regardless of his own wellbeing." I trailed off.
[Track Change: Naruto Shippuden Blood Prison 'Cloudiness']
I looked at Minato. He started thinking, then stopped, whispering,
"No, no, no, no, Obito… you didn't…" Minato started.
Suddenly heavy breathing could be heard nearby, a young Anbu ninja next to Minato was trembling.
I continued, "As Lord Fourth said, his name is Obito Uchiha, who died during the 3rd ninja war, during the battle of Kannabi Bridge, from a boulder landing on him. However this was all orchestrated by Madara and Black Zetsu, who were able to 'rescue him' and restore his crushed right side, including his only remaining Two-Tomoe Sharingan, the other held by his teammate Kakashi.
After Obito's recovery Black Zetsu informed Obito that his old teammates, Kakashi Hatake and Rin Nohara, were being pursued by Mist ninja, without being told that Madara had used Genjutsu to make the Mist ninja kidnap Rin and half-heartedly seal the Three-Tails, Isobu, inside her, making an unstable timebomb Jinchuriki.
Kakashi, who couldn't shake the Mist ninja off and couldn't seal the Three-Tails properly had to engage in combat with the Mist ninja, hoping his sensei, Lord Fourth would arrive in time to help. But Rin took matters into her own hands, committing suicide using Kakashi's jutsu, unfortunately this was seen by Obito as well.
The condition to awaken the Mangekyo Sharingan is a beyond overwhelming stimulus, like witnessing your most cherished persons death. Obito and Kakashi, due to their eyes coming from the same source, each awakened their Mangekyo Sharingan simultaneously, despite Kakashi not being an Uchiha. However, due to Kakashi not being an Uchiha, he is unable to activate this power anymore, and it takes a heavy toll on him constantly."